How to make ChatGPT or Copilot write like you
To make ChatGPT or Copilot write like you, give it real examples of your writing, ask it to describe your style in a short set of rules, and save those rules as standing instructions. After that, every draft starts in your voice instead of the AI's.
Why AI emails sound like AI
Without examples, AI falls back on a polite, padded, middle-of-the-road style: "I hope this email finds you well", three adjectives where one would do, and a closing paragraph nobody needed. Customers notice. The fix is not a cleverer prompt each time. It is teaching the AI your style once.
Step 1: Collect 5 to 10 of your own emails
Pick emails you actually sent and were happy with: a follow-up, a check-in, a proposal note, a short reply. Different situations help. Remove anything confidential before you paste them in.
Step 2: Ask the AI to describe your style
Here are [number] emails I wrote to customers. Study how I write and describe my style as a short list of rules someone else could follow to write like me. Cover: - typical length and sentence length - how I open and close - tone (formal, direct, warm, etc.) - words and phrases I use often - things I never do Then list 5 phrases that are typical of me. [paste emails]
Read the result and correct it. If it says "warm and enthusiastic" and you are actually short and direct, say so. This list is the part that matters.
Step 3: Save it so you never repeat it
Every major AI tool can keep standing instructions. The names differ:
- ChatGPT: custom instructions, or a project with instructions
- Claude: a project with project instructions
- Gemini: a Gem with instructions
- Copilot: depending on your version, saved instructions or a dedicated agent; otherwise keep the rules in a document and add it to your request
Paste your style rules there, plus two of your best example emails.
Step 4: Test and adjust
Ask for a follow-up email you'd normally write and compare it with your own. If something feels off, tell the AI exactly what: "too long", "I never use exclamation marks", "I sign off with just my first name". Add the fix to your saved rules.
Keep a short "never" list in your rules: phrases you would never use. It often makes the biggest difference.
What good looks like
You know it is working when you edit drafts for facts, not for tone. That is the point where follow-ups go from 15 minutes to three.
Related guides
Want this set up for you?
FirstLight OS sets up the AI you already use (ChatGPT, Copilot, Claude or Gemini) with your job, your accounts and your writing style, and adds daily routines with an approval step before anything is sent. One-off payment, from €100.