Structuring the proposal in job sequence is a big help to keep it orderly and precise.
For example, you wouldn't begin with number of coats before you have covered property protection measures and preparation procedures.
A good proposal will also address color choices, sheen choices and paint brands. I like to break those down by room or area.
Mode of payment (don't forget that part)..
In my business, we even cover parking, use of facilities, start and quit times, weekends (yes or no), etc.
Keep in mind, the proposal is not designed to just keep you protected, it's also used to provide a clear scope of work for the one who is paying you.
Michael