Just want to say good on you for applying...a lot of people with potential don't get that far.
Your ASTB scores are fine. They meet the mins. I am a Pilot selectee this year and I think that is identical to what I scored.
I'd basically reiterate what everyone else has said. Make yourself stand out regardless of what category/part of the package you're talking about. Talk to Officers in/around your CoC...even (and especially) if they are going to be on the board. Ask for letters of rec from anyone you can...sit down with them for a few minutes and go over your package, get suggestions, solicit advice, etc.
One thing I don't see mentioned often on here is presentation. I knew an O the first yr I applied who was on the board and he said a quality package (Color copies of everything, well formatted, etc) can make you stand out from the pack not only aesthetically but can get you more points as well. This also goes a long way for your boards. That's what this is...a points game with a little human intervention.