Your thesis proposal is exactly that… a thesis proposal.
A thesis is a statement. Something you was want to prove. Thus your thesis proposal should be one or a few clear statements that you aim to prove in your PhD. Thus, each aim in your proposal should be tailored to outline what you will do to prove this. You’ll want preliminary data and some very mature data, but also each aim should show the steps needed to complete them and what, when they are complete, you will be able to say.
Usually your proposal will have 3 aims.
Aim 1 is usually about complete by the time you have your senate/advance-to-candidacy exam.
Aim 2 usually has substantial progress
Aim 3 is usually more risky, but has preliminary work to show it is doable. You want to ensure, however, that it could be completed within ~18 months.
For each aim do the following
1. Set up the background in just a couple slides
2. highlight the open, unanswered question you will address, and make sure it is clear why it is important.
3. Show preliminary data. Make sure it is directly on topic to answer the question.
4. Show the steps needed to unequivocally answer the question.
5. Have a backup plan ready in case your proposed work fails. What will you get out of it? What other questions would it answer if it failed to prove what you wanted to prove? How could you redirect your work if it’s not turning out well?
You need timelines, a gantt chart, a budget. It must also be clear what you will do, and if you have collaborators doing some work, how you will ensure their parts get done, and what you will do if they flake out on you.
Different committee members and departments have different requirements. However, most committee members expect to see a written document at least two weeks in advance of your exam. Some even require it 3-4 weeks in advance.
You presentation should be ~30 standard PowerPoint slides, and should not take more than 30 minutes to present. Long presentations lead to upset committee members.
Remember, this is an exam. Take it seriously. Make sure your write-up, presentation, and comportment is professional. Also be sure to communicate with your grad coordinator about your committee selection and scheduling of your exams.