Bring a bag you can access fast.

Fanny pack rules for pen, map, and manifest.

Bring a patch kit and CO2 cartridge.
Changing tubes and handpumping can really suck during race.

If you can try to visualize your route. Write major intersection and or checkpoints on your hand or cheat sheet if your brain needs backup.

Think about the route in terms of hills, wind, etc too.

Don't get stressed out at the start. Take your time to make sure you know where you are going or as others suggested stick to a back wheel

Listen to Slayer.

Enjoy!