Ask lots of people to help you improve your proposal. Give it to your colleagues, your friends, your spouse, your dog, and listen to what they say. If they misunderstand what you were trying to say, don’t say “you misunderstood me”; instead rewrite it so it can’t be misunderstood. If they don’t immediately see the value of what you want to achieve, rewrite it until they do.

https://simon.peytonjones.org/great-grant-proposal/