be relaxed (easier said than done) and be yourself. don't pretend to be someone you're not, and don't try to give them the answers you think they want to hear. i just sat on several boards here at USAFA for things and it's obvious who spouted off the "correct" answers from what they thought was wanted. it's not sincere, and it's easy to tell. just try to be yourself and let them get a feel for who you are, not who you think they want you to be