Proofread every carefully prior to submission, keeping in mind that the application documentation is the only thing that will be considered in determining whether or not funds are awarded to your cause.
Ask someone else to proofread the document for you, just to be sure that you didn't overlook anything that needs to be corrected or adjusted.
A good book review follows the same basic rules as any other type of writing: write in the active voice, don't ramble, and proofread your work carefully when you're finished.
Proofread and re-draft any essays until they're the best you can make them, and double-check that all of your materials are complete and professional before you submit them.
Don't miss out on an opportunity for success because of a failure to proofread carefully and have your document reviewed prior to submission.