Making a strong proposal needs to strike a good balance between being short and to the point, but include all key information and background for others to make an informed decision on it. You don’t want those reading it to feel overwhelmed, nor as if you were too lazy to give them a clear explanation of your pitch.
catchy line to capture the essence of your proposal
What is this proposal? What problem do you aim to address?
Any relevant background to understand the context this is being proposed it. Why you are choosing to pitch this now
All the relevant details about your proposal
Links to further material about your proposal that gives it more weight
About the proposer: why are you well suited to do this work?
Total Budget requested and its breakdown into
Deliverables and amounts
Deadlines for deliverables so you can be held accountable