The biggest piece of advice I can give is keep it short and put more important information up front. Every doc should start with a one-sentence plain language description of the thing's purpose and context.

Pascal once wrote in apology "If I had more time, I would have written a shorter letter". Be exactly as detailed as necessary and no longer.

Check out https://diataxis.fr/

I think this "documentation framework" has helped me a lot to write precise docs and how to structure everything regardless of the platform