How-To: Use ChatGPT Projects and Claude Custom Instructions for Repeat Tasks
Stop re-explaining yourself. Save your context once, reuse it forever. This guide shows you how to set up ChatGPT Projects and Claude Custom Instructions so the AI always knows what you need.
Why this matters
Every time you open a new chat, the AI starts with a blank slate. If you keep typing the same context — "Here's my brand voice," "Use this meeting template," "These are my clients" — you're wasting time and risking inconsistency. Projects and Custom Instructions let you save that context once and reuse it across every conversation, so the AI gives you better answers with less prompting.
Step 1. — Set up ChatGPT Projects
ChatGPT Projects (available on Plus, Team, and Enterprise plans) let you group chats, files, and instructions under a single task or topic.
- •Open the ChatGPT sidebar and click New Project.
- •Give the project a name and optionally an icon (e.g. "Email Drafting").
- • Upload reference files — brand guidelines, style guides, examples of past work, templates — that the AI should consult whenever you work in this project.
- •
Write the project's custom instructions. Example:
"You are my email drafting assistant. Always use a professional but warm tone. Reference these brand guidelines for voice and formatting. Default to under 150 words unless I ask otherwise. Never invent facts about the company."
Any new chat started within the Project automatically inherits the files and instructions. Existing chats can be moved into the Project too.
Step 2. — Set up Claude Projects
Anthropic's Claude offers a similar feature called Projects (Pro and Team plans). The workflow is nearly identical:
- •In Claude, open the sidebar and choose Create Project.
- •Name it and add a short description so it's easy to find later.
- • Add knowledge base files — up to 200 files or ~100K tokens of context, depending on plan. PDFs, code files, text docs, and spreadsheets all work.
- •
Write the project instructions. These tell Claude how to behave within the project, e.g.
"You are a research analyst. Summarize uploaded documents with a one-paragraph TL;DR, a bulleted key findings section, and a 'Sources' list citing the document and page number for each claim."
Claude's long context window makes Projects especially good for large documents — legal contracts, research papers, entire manuals.
Step 3. — Custom Instructions vs Projects: when to use which
ChatGPT and Claude both offer a separate Custom Instructions / Personal preferences setting that applies to every conversation, not just one project. Knowing the difference matters:
| Use Custom Instructions for | Use Projects for |
|---|---|
| Global preferences that apply to everything (your name, your job, preferred language, formatting defaults) | Task-specific context (a particular client, a specific product, a recurring report) |
| "Always respond in UK English, plain language, no emoji" | "For this project, you're writing for Acme Corp — use their brand guide and voice" |
| Settings you almost never change | Context you switch between (different projects, different clients) |
A useful rule: Custom Instructions shape how the AI talks; Projects shape what the AI knows for a particular job.
Step 4. — Practical examples
Email drafting project (brand voice)
Upload your brand voice guide and three sample emails you admire. Instructions: "You are a marketing email writer for [Company]. Match the uploaded tone. Every email needs a subject line under 50 characters, a preview text, and one clear call-to-action." Now any chat in this Project produces on-brand drafts instantly.
Meeting notes project (template format)
Upload a blank template and two sample notes. Instructions: "Convert the provided transcript into meeting notes using this exact structure: Attendees, Agenda, Key Decisions, Action Items (with owner + due date), Next Steps. If the transcript is missing something, write 'Not stated' rather than guessing."
Research project (source requirements)
Upload style guides or prior reports as reference. Instructions: "Summarize each source in 3 bullets. For every claim, cite the document name and page. Flag any claim that isn't supported by the uploaded sources with the word UNSUPPORTED."
Step 5. — Tips for writing good project instructions
- • Be specific about role, tone, and format. "You are a concise, friendly email writer who uses short paragraphs" beats "You write emails."
- • Include examples of good output. Paste 1-3 examples of what a great result looks like — the AI mirrors what it sees.
- • Tell it what NOT to do. "Don't use exclamation marks. Don't invent prices. Don't sign off with 'Best regards'." Constraints are as important as instructions.
Quick tips
- •Keep projects focused — one project per task type. A project that does "everything" usually does it poorly.
- •Update reference files regularly so the AI works from current information, not stale documents.
- •Remember that Projects retain conversation history within the project — useful for continuity, but clear old chats if context drifts.
- •Review the first few outputs after creating a project; tweak the instructions based on what you actually get.
Need More Help?
StarCaller Academy offers 1-to-1 sessions to help you with any of these topics and more.