Dorothy Bishop has posted a nice “what not to do” on grant proposals. This was written for psychologists but it applies quite well to any grant work:
In particular, I have to emphasize her comment about enthusiasm
You need to ask yourself “Is this what I most want to spend my life doing over the next 2-3 years?” If the answer is no, then rethink the proposal. If yes, then it’s crucial to convey your enthusiasm.
It is an exciting thing to be paid for what you love doing so make sure that you are asking for money to do something you love… it is hard enough you better at least enjoy it!