1. When you get your rally flag, write your cell phone number on the back of it. In case you leave it at a bonus, the next rider might be able to tell you where you left it.
I recommend carrying a good flashlight. There are a number of bonuses which require you to answer a question, and the information you need may not be all nicely lit up, or located a fair distance off the ground.
And a flashlight will be useful if you're out in a swamp after dark. That one's going to be interesting.