The biggest single article in your package is your personal statement by far. I read a couple personal statements before I wrote mine and I thought they sounded like they had been copied and slightly changed through the selection cycles. I decided to write my personal statement from scratch so I could discuss my shady highschool history, sell my work ethic a little bit and talk about my aspirations in the navy. I also wanted the board to understand my motivation level and how I feel I could help the Navy as an officer.
Remember your personal statement is the first thing the board looks at. It is your one shot to sell yourself personally. Everyone submitting packages to the board are outstanding sailors, workers, leaders. You need to find a way to break yourself out of the pack and make the board say, "This is our guy!".
You can almost gaurantee one thing, everyone you go against will have great evals, good PT scores, awards, LOR's, and decent to great highschool/college histories. So you don't need to tell them about all that stuff because it is almost a given. Tell them about you and what sets you apart from the rest of the Joe Navies.
Also the boards are your next hurdle for selection. Impress the board and get a good recommendation and you should be good. Just relax, be honest, look everybody in the eye when you talk to them, don't fidget, have a squared away uniform....and RELAX. None of the officer's on the boards are there to trick you or "fail" you. They just want to see how you field questions and your critical thinking skills under pressure.