Check out the following link for a guide on creating prompts in Stable Diffusion.
https://stable-diffusion-art.com/prompt-guide/
Stability AI has released a prompting guide for Stable Diffusion 3.5.
You can find it here: https://stability.ai/learning-hub/stable-diffusion-3-5-prompt-guide
You can find a guide to Flux prompting here: https://fluxaistudio.com/blog/prompt-guide