What's your prompt engineering workflow?

Hey makers! 👋
I've been deep in prompt engineering lately while building an AI tool, and I'm genuinely curious about how others approach this.

A few questions:
1. Do you save your best prompts somewhere? Notion, text files, dedicated app, or just copy-paste from chat history?
2. How do you iterate? Do you have a systematic approach or just tweak until it works?
3. Different prompts for different models? Or do you use the same prompt for ChatGPT, Claude, Gemini?
4. Text vs image prompts — do you treat them completely differently?

I've noticed I was doing the same optimizations over and over (adding role, being more specific, structuring output format), which made me wonder if everyone has their own "prompt formula."

Would love to hear your workflows! 🙏