Turn a ChatGPT thread into a reusable prompt: three lines

People leave a good ChatGPT thread in history and start the next similar job with “hi, please write.” History is not a template. A template pastes into a new chat without last week’s mood.

I keep three lines: who you are, what to deliver, what must not appear. Flattery goes. Then I rebuild the same three lines in the on-site Prompt Generator to see if tone or length fell out.

What to cut from the old thread

Find the lines you typed, not the model’s essay. Copy them to a pad. Delete please, thanks, and “as much as possible.”

1. Role: one sentence, e.g. “You rewrite a colleague’s mail and add no new promises.”
2. Task: artifact and length, e.g. “Seven tasks from the notes, each under 20 words.”
3. Bans: a list, e.g. “Do not guess dates. Do not write pep.”

Accept it in a fresh chat

New window. Template plus new source only. If quality drops, the task still contains last week’s proper nouns. Move nouns out. The template keeps structure.

Store the three lines under the job name, not the model name. Models change. Jobs do not.

Do not reuse a whole successful thread as the prompt. That is a log. It smuggles old facts into a new draft.