A proposal is a binding offer. If the client accepts, you are contracted on exactly the terms you wrote.
What to include
- Your reading of the problem, in your own words. This alone separates you from the field. It proves you read the brief.
- Your approach, named concretely. Which method, which tool, why.
- Milestones, each ending in something the client can assess.
- Fee per milestone.
- Deadline per milestone.
- Revisions included, and within what scope.
State the revision scope
"Two revisions within the agreed scope" prevents the most common dispute on the platform. Leave it vague and you will be asked for unlimited rework.
Do not promise results
You can promise an analysis. You cannot honestly promise a finding. Never suggest a result will be significant, publishable, or accepted. You do not control any of that, and promising it is a dispute you will lose.
Before sending
Re-read it as the client. Is the scope unambiguous? Could you deliver this at this price by this date, on a bad week? If not, change it now, not after it is accepted.