Yesterday I took 3 client inquiries. Just on "background context" I typed 200 characters.
Every time I opened Claude I had to retype: I'm a freelance designer, I do Xiaohongshu visuals, my clients are small-medium brands, copy should be conversational but not too casual...
I repeated this background at least 50 times. Later I found out Claude officially has this "system prompt" feature — write it once at the top of the conversation and it follows throughout. I only just figured this out myself — I'd been dumbly retyping context every single time.
What system prompt is + who's already using it
Think of system prompt as "the employment contract you sign with Claude." You tell it: who you are, what clients you serve, what tone, what's off-limits — it follows from then on, no need to repeat.
Anthropic recently made this an official standard setting (it used to be buried inside Projects), so regular users can access it too.
My friend Xiaoli, 30, has been running Xiaohongshu agency operations in Hangzhou for 2 years. She put "viral opener formulas + client industry banned words + her tone preferences" all into her system prompt — now she gets a draft in 5 minutes; it used to take 20 minutes just to train the AI.
Your cost to replicate this today
Money: $0. Free tier supports it; Pro (~$14/month) lets you save more Projects.
Time: First write takes about 30 minutes. I messed this up — I initially wrote 800 characters and Claude actually ignored me more; trimmed to under 200 and it ran smoothly.
Technical barrier: If you can type, you can do this. No code involved.
First step: Open claude.ai → click the top-left avatar → find "Projects" or "Custom Instructions" → fill in the four sections: who you are + who you help + your tone + your taboos → save. Apply it directly in your next new chat.
How to use it at each stage
If you're just starting: Don't rush to build a Project. Write a system prompt for the 3 things you do most (write copy, reply to clients, draft proposals), stash them in a memo app, paste at the top of each chat.
If you already have 1-2 stable clients: I suggest building 3 Projects — consultation-type, repeat-type, referral-type — each with a slightly different system prompt.
If you're scaling up (starting to hire part-timers/assistants): Turn your system prompt into an SOP and share it with them. New hires can use your "tone" with clients on day one — no need to coach them sentence by sentence.
This tool isn't for everyone — if you only use Claude once a week, don't bother. But if you use it daily, those 10 minutes saved add up to 40 hours over half a year.