Below are tips to help you write a reviewer friendly proposal. 

Left align your text, do not justify

Font size should be 12

Font type should be Century Schoolbook or Times New Roman

Bold headings and subheadings is acceptable

Use the same font type and size throughout your proposal (be consistent)

Use brief sentences as much as possible (a person will usually only remember 2 lines of text before forgetting the beginning of the sentence)

Diagrams and figures should be well designed and add to the proposal

Proof your proposal (it must be error free with no whiteouts)

Proposal should be written with the optimism of success

Address all application requirements in your proposal in the same order that they are listed in the Request for Proposal

Follow the requirements/criteria list for both the applicant and the reviewer

Include a table of contents to lead the reviewer to all requirements and review criteria (this will be helpful for the reviewer and save time)

Budget should cover the cost of the research proposed and establish the feasibility of the project

Do not add what is not requested

Have at least one of your peers review your proposal

Consult books/articles on grant writing (The Graduate School can provide a list of references)

All of these tips are aimed at helping the reviewer review your proposal.  The better you create/construct your proposal the easier your reviewer will have in evaluating the merit of your research.  Remember these reviewers may have hundreds of proposals to evaluate with limited time.  If your proposal is easy to read and follow, concise and valid you are already ahead of the game and the reviewer will appreciate a break from having to struggle through looking for the application requirements.