The best way to save a prompt you use every week is to split it into two parts, the rules that never change and the blanks that do, and put the rules in a ChatGPT Project's instructions. After that, a one-line request inside the project gets the full result, which is exactly what you build in the free lesson Turn a Great Prompt into Reusable Instructions.
ChatGPT has no "save prompt" button in the message box. You have three good places to keep a prompt, and which one fits depends on how often you use it and whether it needs files.
Where can I keep a prompt?
| Where | Best for | How you reuse it |
|---|---|---|
| A document of templates | Prompts you use now and then, in any AI tool | Copy, fill the blanks, paste |
| A ChatGPT Project | A job you do every week, with its own files | Type a short request in the project |
| Custom instructions | Rules for every chat you have, like your tone | They apply on their own |
A document of tested prompts is a prompt library, and each prompt with blanks in it is a prompt template. The post on custom instructions vs project instructions explains the difference between the last two rows.
What are the steps to turn a prompt into Project instructions?
- Start with a prompt that already works. Do not save a prompt you have not tested.
- Ask ChatGPT to sort it. Paste the prompt and ask it to split it into instructions (rules true for every job) and a list of what to send each time (the blanks).
- Create a project. In the sidebar, point at Projects and click the +, or click New project. Name it after the job.
- Paste the rules. Click the ⋯ next to Share, choose Project settings, paste into Instructions and click Save. Closing with the X throws the text away.
- Test with a one-line request. Type only the blanks, for example the customer and the job.
- Fix the gap you find. Add one rule at a time, save, and test again.
What does this look like in a real lesson?
In Turn a Great Prompt into Reusable Instructions, Mike at a made-up heating and air company pastes a long estimate prompt every time. ChatGPT sorts it into the rules (format, haul-away included, quotes good for 30 days) and the blanks (customer, address, job, prices). You create a project called Ridgeline Estimates, paste the rules into its instructions and save.
Then you test it with one line: "Estimate for Dave Kim, 9 Oak St: replace his 3-ton AC condenser, 1-day install." The format and the 30-day line come straight from the instructions, but the Total line shows a gap: the rules never said what to do when no prices were given. You add one rule, "if the prices, name or address are missing, ask first", save, and send the same request. This time ChatGPT asks for the prices before it writes anything, and you check every line of the estimate against the prices you sent.
If the job also needs files, like a price list or a style guide, ChatGPT Projects: Your Brand Voice in One Place adds them as project sources next to the instructions.
What about Claude?
Claude Projects work the same way: instructions plus project knowledge. Claude also has skills, which suit a task you want done the same way every time, such as a weekly report. In build your own skill with the skill creator, Claude interviews you about a painting company's Friday job report, drafts the skill, tests it on a real week of crew notes and packages it. Afterwards a plain "Can you do the weekly report?" loads the skill on its own.
What mistakes should I avoid?
- Saving one long prompt with everything in it. Rules go in instructions, changing details go in each request.
- Not testing the saved version. The first one-line test usually finds a gap.
- Putting client data in instructions. Instructions and project files are for business rules and templates, not for private records.
- Fixing the same problem in every chat. When a reply misses something, change the instructions once.
- Losing your best prompts. Keep a copy in a document too, so you can use them in other tools.
Key takeaways
- Split a proven prompt into rules and blanks.
- Put the rules in a Project's instructions, then send one-line requests.
- Keep a document of templates for prompts you use in different tools.
- Test, find the gap and add one rule at a time.
- In Claude, a skill is the home for a task done the same way every time.
Frequently asked questions
- Can I save prompts on the free ChatGPT plan?
Yes. Projects and custom instructions are available on the Free plan, and a document of templates works anywhere.
- Is a Project better than custom instructions?
For one job, yes, because the rules apply only inside that project and can sit next to its files. Custom instructions apply to every chat, so keep them to general preferences like tone.
- Can my team use the same saved prompt?
Share the template document, or share the project itself if your plan supports shared projects. Check that everyone uses the same latest version.