The keys to the office.
You finished Unit 2 with a sharp briefing skill. This unit ends the part where you have to use it. By the end you'll know how to write your briefs once and have Claude read them forever.
This is where most working professionals stop. Not because Phase 3 is hard — because they don't know it exists. They learned to prompt well in Phase 2 and assumed that was the destination.
It isn't. Phase 2 is the lobby. Phase 3 is the office. In Phase 3 the work you did in Unit 2 — defining a Role, writing Context, naming Constraints — doesn't get wasted. It gets promoted. Instead of typing it once per session, you write it once and it shows up forever.
What you'll walk out with
A new mental model: context doesn't live in prompts — it lives in your setup. A working understanding of the three mechanisms — Projects, Custom Instructions, and Reference Files. And two completed sample setups: your first Project plan and your first one-page Custom Instructions, both ready to use this week.
What Unit 3 covers
- The Phase 2 tax — the hidden cost of staying in briefing mode forever.
- The mindset shift — from "in your prompt" to "in your setup."
- The three mechanisms — Projects, Custom Instructions, Reference Files. What each does and what each is not for.
- Two worked examples — Linda the HR director builds her Project, Tina the consultant writes her standing brief.
- Three Phase 3 mistakes — and the fix for each.
- Two hands-on briefs — you plan your first Project, you draft your own Custom Instructions.
- The Phase 3 ceiling — what even a perfect setup can't do, and what comes next.
The hidden cost of Phase 2.
Briefing works. It also costs you a full work week per year if you don't graduate. Here's the math nobody runs.
Once briefing becomes your default, the quality of your work with Claude goes up and stays up. You will not go back to Phase 1. But after a few weeks, a quieter problem shows up — and most professionals never name it.
You're paying a tax.
Every Phase 2 conversation starts the same way: you re-type the Role. You re-paste the Context. You restate the Constraints. The brief works. The brief also has to be rewritten every single session because Claude opens blank.
That repetition has a name in this course. It's the Phase 2 tax — the recurring cost of context that lives in the prompt rather than in the setup.
The Phase 2 Tax — a real calculation
That's three full work days per year typing the same sentences. Not because you needed to think them — you already had them in your head. Because Claude had no place to remember them.
The quality cost is sneakier.
The time math is the obvious version. The quieter version: when you re-type the same brief for the hundredth time, you cut corners. Tuesday's version was complete. Thursday's is missing a Constraint because you were in a hurry. Friday's left out the Role because it felt obvious. Your output quality starts to wobble for no obvious reason.
A setup that holds the brief doesn't have a bad day. That's the real reason to graduate.
Reflection · 2 minutes
How many times this week have you re-typed the same role, the same company context, or the same writing constraints? Estimate honestly.
Move it out of the prompt.
The shift sounds small. Move context from the prompt into the setup. What changes is the friction of every single conversation, every single day.
In Phase 2 your prompt does two jobs. It tells Claude what you want done. It also tells Claude who you are, what your company does, what your customers care about, and what "good" looks like. The first job is the task. The second job is the setup — and Phase 3 separates them.
The slogan that does the work
Write the brief once. Read it forever.
The work you did in Unit 2 — defining Role, writing Context, naming Constraints — was real. In Phase 3, you do that work one time instead of every time. Claude opens already knowing.
The new-employee analogy, sharpened
Imagine the same colleague from Unit 2. Day one, you had to brief them before every task. By week six, you didn't. Why? Not because they got smarter. Because they had been around long enough to absorb the basics — who the customers are, what the company sells, how your team writes, what's off-limits. You stopped briefing because they stopped needing it.
Claude doesn't absorb anything between sessions — by default. Phase 3 is where you give Claude the equivalent of those six weeks. Up front. Permanently.
What your Phase 2 prompts will look like in Phase 3
Shorter. Sharper. Almost embarrassingly light. Where you used to write 200 words of brief plus 30 words of task, you'll write 10 words of task — because the 200 words of brief now live in your setup and Claude is reading them before you finish hitting enter.
That isn't a step down in rigor. It's the opposite. The rigor moved upstream. Your prompts get to be short because your setup is heavy.
Three places context can live.
Persistent context comes in three shapes. Each one does something the other two don't. Most working professionals end up using all three — layered.
Before you build anything, understand what goes where. The biggest Phase 3 mistakes are not technical — they're putting the wrong content in the wrong mechanism.
Projects
A dedicated workspace inside Claude for one domain of your work. You give it a name, load reference files, set domain-specific instructions, and from then on every conversation inside that Project inherits all of it.
Custom Instructions
A short, standing brief that applies to every conversation you have with Claude. Your identity, your voice, your universal preferences. You write it once. Claude reads it before every reply, in every chat, in every project.
Reference Files
Documents you attach to a single conversation when you need them. A specific customer contract. A meeting transcript. A long policy doc you want Claude to read once. Less elegant than a Project — and more flexible.
The layering rule
Universal → Custom Instructions. Domain → Projects. One-off → Reference Files. A well-set-up professional has 1 set of Custom Instructions, 3 to 7 Projects, and Reference Files coming and going as needed. That's the shape.
Linda builds her Policy Q&A Project.
You met Linda in Unit 1 — HR director at a 300-person logistics company. Saturday morning. Two hours. One Project that changes her Monday forever.
Linda's problem: managers ping her with policy questions all day. "Can someone use PTO to extend bereavement?" "What's the rule on remote-work eligibility for our hourly staff?" "How does our holiday pay work for the warehouse schedule?" Most of these are already documented somewhere — in the employee handbook, in the PTO matrix, in benefits summaries — but nobody wants to dig.
What she sets up
Project name
Policy Q&A
Reference files loaded (4 total)
- Current employee handbook (PDF, 92 pages, dated this quarter)
- PTO matrix (spreadsheet showing accrual by tenure and role)
- Benefits summary deck (current plan year)
- FMLA & bereavement policy (separate PDF, frequently asked)
Project-level instructions (what Claude reads on every chat in this Project)
You are a friendly HR partner answering policy questions for managers at our logistics company. Always cite the specific section, page, or document name in your answer so the manager can verify. Never speculate. If the documents don't cover the question, say so directly and recommend the manager email me. Default to plain language. No HR jargon, no acronyms unless you spell them out the first time.
What she didn't put in
This is where the discipline shows up. Linda left out: legal counsel correspondence, draft policy revisions that aren't approved yet, individual employee files, performance documentation, and the old (now-retired) handbook from two years ago. Each one of those would have been "more context" that quietly degraded every answer.
Curation is a feature, not a limitation
The Project knows what you want it to know. It doesn't know what you want it not to know — unless you don't load it. 3 to 5 high-signal documents almost always beat 50 mediocre ones.
The Monday morning test
First Monday after Linda ships it: a regional manager asks, "If a salaried supervisor wants to use PTO to extend three days of bereavement, what's the rule?" Linda's Project responds: "The bereavement policy (page 41 of the handbook) covers 3 days for immediate family. Per the PTO matrix, salaried staff may apply available PTO to extend bereavement — this is at the supervisor's discretion. The employee should submit a PTO request through the normal portal. (See handbook section 7.3.)"
The manager has their answer. They didn't email Linda. By the end of the week, four managers had self-served on routine policy questions that would have been four interruptions to Linda's actual work.
Tina writes her standing brief.
Different mechanism, different professional, same kind of payoff. Tina is an independent management consultant. Her writing voice is everything — and Custom Instructions are how she preserves it across every conversation.
Tina works with mid-market manufacturing companies — 50 to 500 employees, mostly family-owned, mostly Midwest. Her writing voice is distinctive: tight, plain, no MBA-speak. Her clients hire her partly for her brain and partly for how she sounds on the page.
Before Phase 3, Tina pasted a voice paragraph at the start of every Claude conversation. After Phase 3, she wrote it once. Here it is, verbatim, the way she actually has it set:
Tina's Custom Instructions
IDENTITY. I'm an independent management consultant working with mid-market US manufacturers (50–500 employees, mostly family-owned). My clients are typically the owner, COO, or president — not professional executives.
VOICE. Tight, direct, plain English. Active voice. Short paragraphs. No MBA-speak. No words like "leverage," "synergize," "stakeholder ecosystem." Write the way a smart operator would talk over coffee — not the way a McKinsey deck reads.
FORMAT. Default to bullets for analysis, prose for client-facing deliverables. Always state your assumptions before your conclusions. If you're not sure of something, say so explicitly rather than hedge.
NEVER. Open an email with "I hope this finds you well." Use the phrases "at the end of the day," "moving forward," "circle back," or "bandwidth." Recommend a framework I haven't asked for.
What you'll notice
- Specific, not vague. Not "be professional" — but "no exclamation points," "active voice," "bullets for analysis." Every line is a rule Claude can actually act on.
- Universal, not project-specific. There's no mention of any particular client, any particular industry deep-dive, any particular deliverable. Those things belong in Projects. Custom Instructions stay universal.
- Identity + Voice + Format + Never. A useful template you can borrow as the shape of your own.
What changes for Tina day-to-day
Before: every Claude conversation started with a voice paragraph she pasted from a note. Sometimes she forgot a rule. Sometimes she was in a hurry and pasted half of it. Output quality wobbled.
After: she just writes the task. "Draft the kickoff agenda for our session with Hawkins Manufacturing on Thursday." The voice, format, and rules show up automatically. The first draft sounds like her on the first try.
That's the entire promise of Phase 3 in one example. The brief is in the setup. The prompt is just the task.
Reflection · 3 minutes
If you had to write Tina-style Custom Instructions for yourself, what's the first line of each section? Identity, Voice, Format, Never.
Three mistakes that turn good setups into bad ones.
Once you start building Projects and writing Custom Instructions, you'll hit one of these within the first week. Spot them early — the fixes are simple.
Mistake 1 — Over-stuffing the Project.
You dump every document you've ever written into a Project. It feels thorough. In practice, the output gets worse — Claude pulls from irrelevant docs, mixes contexts, hedges because the source material conflicts. More signal becomes more noise.
Mistake 2 — Custom Instructions that try to do everything.
You start writing your standing brief and it grows to 800 words. It tries to specify rules for every type of work you do. The problem: rules that fit your sales emails don't fit your board memos — and now both are being shaped by instructions that don't actually apply.
Mistake 3 — Set it and forget it.
You build your Project in February. By October your reference files reflect the world as it was 8 months ago. Claude is giving confident, well-formatted answers based on stale information — which is worse than no answer, because they feel right.
The debugging move
When a Phase 3 answer feels off, check the source. What in my setup made this answer the way it is? Nine times out of ten, the fix is in the Project files or the Custom Instructions — not in the prompt.
Your turn.
Two sample projects again. You plan your first Project. You draft your first Custom Instructions. The goal is to leave Unit 3 with two artifacts you could actually use this week.
Plan your first Project.
Think about the area of your work where you find yourself talking to Claude the most. Customer emails? Weekly reports? A specific kind of analysis? Pick one — narrow, not your whole job — and plan a Project for it.
Fill in the four fields below. Don't worry about the platform mechanics. This is the planning artifact you'd hand to your future self when you go to build it.
One way to plan this Project
Project name: Investor Update (weekly).
3–5 files: (1) Most recent 8 weekly updates I've sent. (2) Current cap table summary. (3) Current quarterly plan with targets. (4) Last board deck. (5) Our written tone guide.
Instructions: You are drafting weekly investor updates from me (the CEO) to a small group of seed investors. They are sharp and busy. They want the headline numbers, then the most important development of the week, then any specific ask. Tone is direct, honest, lightly informal — not corporate. Always show numbers as raw figures with one-line context, not percentages alone. If a week was bad, name it; don't spin.
Never do: Use the phrase "we're heads-down" or "we're crushing it." Open with a generic intro. Bury bad news under wins.
Notice the curation. The model answer loads exactly 5 files — past examples (for voice), reference data (for accuracy), and a tone guide. It doesn't load the company wiki or every customer email. The discipline is in what's left out.
Write your standing brief.
Use Tina's template from page 6: Identity, Voice, Format, Never. Keep it tight — under 200 words total. This will apply to every Claude conversation you have, in every Project.
Your Custom Instructions.
Write the standing brief you'd want Claude to read before every reply, in every chat. Universal stuff only. If a rule only applies to one type of work, it belongs in a Project — not here.
One way to write this — for a sales operations leader
Identity: I'm the head of sales operations at a 90-person B2B software company. My day is split between sales leaders, finance, and revenue analytics. I write for sharp internal audiences who want the numbers and the call.
Voice: Direct, conversational, plain English. Active voice. Short sentences. No filler phrases. I write the way I'd talk in a 1:1 — not the way an enablement deck reads.
Format: Default to bullets for analysis, prose for narrative or sensitive communication. Always lead with the recommendation, then the supporting numbers, then the caveats. Show your reasoning if it's not obvious.
Never: Use the words "leverage" or "synergize." Start an email with "I hope this finds you well." Hedge a recommendation behind three qualifiers — pick one.
What this is not. It's not 800 words. It's not trying to cover every situation. It captures who this person is, how they sound, and what makes their output recognizable. Domain-specific stuff lives in Projects — Custom Instructions stay clean.
One layered habit
By the end of this unit you should have one set of Custom Instructions (universal you) plus at least one Project (a specific domain of work). That combination is what Phase 3 actually looks like in practice. Everything else is just more Projects.
Even a perfect setup has a limit.
You'll get a few weeks of feeling like Claude is finally yours. Then a new friction will show up — and that's the entire setup for Unit 4.
Phase 3 changes your relationship with Claude permanently. Your setup is doing real work. Your prompts get to be short. Your output quality stops wobbling. You stop teaching the same lesson every Monday.
But here's what hasn't changed: you still have to tell Claude what to do. Every. Single. Time.
The task-repetition problem
Even with rich Projects and tight Custom Instructions, you find yourself typing the same kind of task over and over. "Run this week's marketing recap." "Draft the standard client kickoff email." "Generate a quarterly board memo using last quarter's structure." The setup is loaded. The task itself is still on you to type.
For a long time, you'll do that without noticing. Then one Friday afternoon you'll catch yourself typing — for the twentieth time this month — what amounts to the same instructions. Word for word. Different inputs, same instructions.
The signal you're ready for Phase 4
When you catch yourself thinking "I just want to say 'run the X' and have it happen" — you've outgrown Phase 3. The next unit is about packaging that "X" so it just runs.
What Phase 4 actually fixes
Phase 4 — Delegate — packages your recurring tasks into Skills. A Skill is an instruction set Claude loads automatically when the task matches. You define it once. From then on, you just trigger it — "run the Monday recap" — and Claude follows the procedure.
The work you just did in Phase 3 doesn't get replaced. It gets built on top of. Your setup holds the who and the what. Skills hold the how. Together they turn entire workflows into one-line triggers.
Reflection · 2 minutes
What's one task you've done with Claude five or more times where the instructions barely change? (That's the first Skill you'll build in Unit 4.)
Are you ready to move to Delegate?
Three questions to diagnose whether you're ready for Unit 4 (Skills) — or whether you need another week or two with your new Phase 3 setup first.
1. Where does most of your context live today?
2. How often do you find yourself typing the same kind of task into Claude?
3. When Claude gives you a weak answer, what's your first instinct now?
Your readiness
Answer all three questions above to see your readiness for Phase 4.
Seven questions.
One per major idea in this unit. Click an answer for instant feedback. Your running score appears below.
0 of 7 answered · 0 correct so far
1. What is the "Phase 2 tax"?
2. What is the defining mindset shift from Phase 2 to Phase 3?
3. The three mechanisms of Phase 3 are:
4. Which kind of content belongs in Custom Instructions (and NOT in a Project)?
5. The most common Project mistake — and the one that quietly degrades output the most — is:
6. Which of these is a strong Custom Instruction line?
7. What is the Phase 3 ceiling — the limit even a perfect setup can't push through?
Finish the knowledge check to see your score.
All your reflections, your Project plan, and your Custom Instructions are saved — come back anytime.
The new thought process.
Write the brief once. Read it forever.
Context doesn't live in prompts. It lives in your setup. The work you did in Unit 2 is done — now it just runs.
Three mechanisms, three jobs.
Projects = a workspace for one domain. Custom Instructions = the universal you. Reference Files = the bookshelf you pull from when needed.
Curation is the skill.
Three to five high-signal files beat fifty mediocre ones. What you leave out matters as much as what you put in.
Task repetition is the doorway.
When you find yourself typing the same kind of task over and over, you're ready for Phase 4. Skills package the task itself.