turtle sc,
The only advice I can give you is to be yourself. Even officers can smell BS. When I went to my boards I was worried that I would need better evals, scores etc. but I think the one thing that impressed them the most was my candor. I'm a diggit: so I told them straight up... I don't care if I get selected I just think being an officer would be helpful to myself and the Navy.
Confidence and Honesty.