How to Teach ChatGPT Your Writing Style: A Prompt Guide

Build the style guide

Asking an AI to "write in a friendly tone" gets you the model's idea of friendly, not yours. Your style lives in details: how long your sentences run, what you never say, how you open and close. You can get a much closer draft by showing the model those details directly. This takes about twenty minutes to set up, and you can reuse the result for months.

Step 1: collect real samples. Gather three to five pieces you wrote yourself and like, about 300 to 500 words each. Pick writing done without AI, and choose the type you want to produce: use emails to teach email style, articles for articles. Before pasting anything into an AI tool, remove private details about clients, colleagues or your employer, and check your company's rules on sharing internal documents.

Step 2: ask for an analysis, not a rewrite. Paste the samples and use a prompt like this: "Analyze the writing style of these samples. Describe sentence length and variety, vocabulary level, tone, how paragraphs open and close, punctuation habits, and any phrases or patterns that repeat. Give specific examples from the text. Do not rewrite anything." You want a description you can read and correct.

Step 3: correct the description. The analysis will be partly right. Fix what it missed, and add rules only you know. Useful additions are things you avoid: no exclamation marks, never "delve" or "leverage", no rhetorical questions, contractions always. Negative rules are often more useful than positive ones, since they block the defaults you want to avoid.

Use it on real drafts

Step 4: turn it into a style guide. Ask the model to compress everything into a short set of instructions, around 150 words, plus one sample paragraph. Save it somewhere you can reach it. Many tools let you store it as custom instructions or in a project. If not, paste it at the start of each new chat.

Step 5: write with notes, not just topics. A style guide fixes the voice, but the content still needs to come from you. Try: "Using the style guide above, turn these notes into a draft. Keep to my points. Do not add claims, examples or statistics that are not in the notes. If something is missing, ask me instead of inventing it." That last sentence matters, because it stops the model from filling gaps with invented detail.

What this will not do

Step 6: fix the first draft by giving feedback. Point at specific lines: "Sentence two is too formal. I would never write the last paragraph. Cut it." When you notice the same correction twice, add it to the style guide so the guide keeps improving.

What this will not do. Models drift, especially in long chats, so paste the guide again if the voice starts to slip. A style guide also cannot supply your experience or opinions, and the draft still needs a fact-check. For the leftover stock phrases and even rhythm, a humanizer pass plus a read-aloud usually finishes the job.