Good to hear you did well!
As for prep... I try find not sleeping the night before works for me. I drink lots of coffe and have no breakfast the next day, and end up running for the bathroom JUST before and after each run.
Okay, that's what I DO do, but not what I SHOULD do. =D haha... I TRY to get to sleep, but am always bogged down with repairs/fluid changes the night before... I'm often too excited to sleep for the few hours that I could possibly get anyway. Then I finally get to bed 5 minutes before my alarm goes off, and I end up getting out of the house LATE and not having time for breakfast and usually forgetting to bring water to the event.
haha... great, isn't it?
What I would do, mentally though, is one of two things: let the competitive spirit take over (when you're in that sorta meditative, calm state) or if you just can't shake the nerve, I go back to thinking of all the fun that driving is for me, and trivializing the embarrassment that's about to come when you eat 3 cones.
haha... trivialization and turning a competition into *pure* fun works well.