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Module 26 · ~12 min

Custom GPTs / Claude Projects (Beginner)

Build your first reusable assistant — no code, one afternoon.

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The big idea

💡Key idea
Every time you re-explain your context to a fresh chat, you're paying a tax that Projects and Custom GPTs eliminate — you set up instructions and a few key files once, and every future conversation in that space starts already knowing your situation. The trap to avoid is overloading it; a lean setup beats a bloated one every time.
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  1. Projects exist to solve:

Deep dive

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Every fresh AI conversation starts from zero — it doesn't know your job, your family situation, your writing voice, or the project you're working on unless you tell it, every single time. For anything you do repeatedly, that re-explanation becomes a real, recurring tax on your time.

This is the exact problem Projects (Claude) and Custom GPTs (ChatGPT) solve: a persistent space where your context — instructions, files, prior chats — lives once and applies automatically to every new conversation started inside it.

Recognizing this pattern in your own life is the first step: any task you find yourself explaining the same background for repeatedly (your household situation, your team's writing style, your side-project's details) is a strong candidate for its own Project.

A Project is essentially a folder that bundles three things together: standing instructions (context that applies to every chat in the Project), reference files (documents that define important context), and the chat history itself, all in one place.

This bundling is what makes it more useful than just a regular chat — instead of a single conversation that eventually gets long and messy, you get a persistent space where new chats automatically inherit the setup, and you can start a fresh, focused conversation anytime without losing the context.

Think of it as setting up a well-organized desk for a specific area of your life once, rather than re-explaining your situation from an empty desk every single time you sit down.

Good standing instructions are short and structured, covering a handful of specific things: who you are and your context (identity), who the output is usually for (audience), how it should sound (tone), what format you typically want (format), and anything you specifically don't want (bans — like "never use corporate jargon" or "never suggest generic filler text").

This structure works because each element answers a question the AI would otherwise have to guess at every time, and guessing is where generic, unhelpful output comes from. A few well-chosen sentences covering these five areas outperform a long, meandering essay by a wide margin.

The discipline here is brevity: aim for roughly 5–10 sharp lines rather than trying to capture every possible nuance up front — you'll refine based on what actually goes wrong, not by trying to anticipate everything in advance.

Beyond instructions, a Project can hold reference files that give it deeper context — a household's recipe list and budget categories, a curriculum document, a style guide. The key discipline is choosing a small number of files that genuinely define your context, not everything that might conceivably be relevant.

Three to five well-chosen documents beat thirty loosely-related ones, because every file adds content the AI has to weigh against everything else — more isn't automatically more useful, and past a certain point it actively dilutes focus.

A good test for whether a file belongs: would leaving it out actually cause the AI to miss something important in a typical request? If a file doesn't pass that test, it's probably not worth including yet.

Custom GPTs work similarly to Projects — instructions plus files — but with one key difference: they're built to be shared with other people, who can use your setup without needing to see or understand how it was configured.

This matters for a specific use case: when you're not the only person who needs the assistant. A teacher building a quiz generator for colleagues, or a team lead building a standard-format report generator for their group, benefits from a Custom GPT precisely because others can use it with zero setup on their end.

The decision rule is simple: if it's just for you, a private Project is usually simpler and sufficient. If other people need to use the exact same setup, a Custom GPT is the right tool.

Once you've written instructions and added files, don't assume it's finished — run a shakedown of five typical requests you'd realistically make, and see where the output falls short of what you actually wanted.

This testing phase is where the real tuning happens: a vague instruction line often looks fine on paper but produces mushy or off-target output in practice, and you only discover this by actually using the thing the way you plan to use it going forward.

Each miss is useful information — fix the specific instruction or file that caused it, then note how the fix changed the next similar request. This iterative loop, done once upfront, saves much larger frustration later.

Rather than one giant, all-purpose Project trying to cover everything, it works better to build separate Projects for genuinely distinct areas of your life — work, a side project, household and finances. Each has different context, different tone, and different typical requests.

This separation keeps each Project's instructions and files focused and relevant, instead of a single bloated setup trying to serve unrelated purposes and doing none of them particularly well.

A reasonable starting point for most people is two or three Projects covering their biggest recurring areas, expanding to more only once each existing one has proven genuinely useful and well-tuned.

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  1. Good starting instructions are:

In the field

🔬Worked example
Example 1: "Household Manager" Project. Instructions: family size, dietary rules, budget philosophy, tone (practical, zero guilt). Files: favorite-recipes list, monthly budget categories. Now "plan next week's dinners" or "categorize this statement" needs one line, not one paragraph. Example 2: A teacher builds a custom GPT "Quiz Builder" with instructions (grade level, question style, difficulty ladder) and the curriculum PDF — then shares it with two colleagues, who now generate consistent quizzes without learning any of the setup.
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  1. Choose a custom GPT over a Project when:

Pitfalls & takeaways

Failure modes

  • Stuffing dozens of files and long essays into instructions, which makes output mushier and slower rather than better
  • Never running a real shakedown test, so problems in the setup surface later, during actual use, instead of upfront
  • Building a Custom GPT to share when a private Project would have been simpler and sufficient
  • Treating the setup as one-and-done instead of refining instructions as failures reveal what's missing

Durable takeaways

  • Projects bundle instructions, files, and chats so you stop re-explaining your context every conversation
  • Keep instructions short (5–10 lines) and files few (3–5) — bloat makes output mushier, not better
  • Use a Custom GPT when others need to use the exact same setup; use a private Project when it's just for you
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  1. If Project output is mushy/generic, first suspect:

Do the work

🏋️Prove you learned it

Build one Project for your biggest recurring context. Write ≤10 instruction lines, add 2 files, then run the shakedown: five typical requests. Fix instructions where output missed; note how each fix changes results.

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Sources

  • · https://help.openai.com
  • · https://docs.anthropic.com
  • · https://www.oneusefulthing.org