I know it's too late to post my tips for the OP, but maybe someone else will gain from my biggest mistakes...
Like someone else mentioned, be the professional pilot.
Stand up for your decisions. During my oral, I planned a flight in a manner that was safe and I was comfortable with, but not how the examiner would have planned it. Using his ninja questioning skills, he had me second guessing myself and my choice of route. Once you start second guessing yourself, you cease to be the one in control of the flight and you begin second guessing other things. Luckily, I nipped it in the bud before it was too late.
On the other hand, admit it when you are wrong and volunteer to correct it ASAP.
Be able to identify why something didn't go right during a flight. My power off 180 was really crappy (was going to land 50' too short of the runway), I identified what I did wrong and things went fine.