Specififc Aims

Components:

Intro paragraph: The writing on a specific aims page is very formulaic. You need a traditional hook to introduce your subject area and then include a few sentences on background information. This paragraph should be used to frame your project in the broader picture of what is known, what is unknown, and how your project is needed to fill some critical gap.
Hypothesis/Proposal paragraph: Now after you introduce the purpose of your project, it is time to talk about the specififcs of your proposal. In this paragraph you will actually include your hypothesis written in a hypothesis format. It can be useful to underline your hypothesis sentence to make sure it is clear and you may want to even write it as "we will test the hypothesis that....".
Aims: An aim for your research proposal is a specific objective of your study. It has to be framed in a manner that makes it apparent when and how the aim will be achieved. Essentially, your aim should have some specific tangible result that is clearly achievable. Aims also shouldn't be dependent upon eachother. Interdependent aims weaken your proposal as if one aim fails, it is likely that the other aim will fail as well.
Impact statement: After you state your aims, you conclude with a short paragraph indicating the significance of your research. What is the broader scope of your project. By completing this work, what will you contribute to the field and why is it important (health, technology, etc)? Other things to consider when writing this paragraph are 1.) expected outcomes and 2.) innovcation of your work/strategy.

Number of Aims: You need at least 2 aims but up to 4 is allowable. I think it is more common to see 2-3 aims but 4 is not unheard of. When developing these it is useful to get advice from your PI.

Underlining: To emphasize important points for your reviewer, you may consider underlining sentences (anything that helps the reviewer helps you). In the first 2 paragraphs, you may consider underlining any of your preliminary data and/or your stated hypothesis. In your aims statements, it can be helpful to highlight the goal of each aim which is usually the last sentence. The impact statement should be very brief so I usually don't underline any statements there.

Fluff: The specific aims page has a 1 page limit, but you will want to fill the whole page while remaining succint. In general, you want to make sure every single sentence is important and relevant, but it is particularly important here due to page limit. A specific aims page is definitely no place for fluff. However, this does not mean you have to worry about being redundant with information/ideas from other locations. In fact it is probably good to be redundant (within reason) across the research proposal, specific aims, abstract, and other researcch statements in your proposal to make sure that the reviewers remember what your research is about. Just make sure not to completely copy and paste. It is better to paraphrase and rewrite statments. I think writing the same thing but in different ways should also help push across your point.

Very helpful links:

Advice from a Grad Student.

Specififc Aims