I eat as much as possible the day before, use Hammer Perpetuem during the race (when i remember to drink, lol). Water too, of course, and some clif bars. Of course I've only done 2 solo races, but this strategy has kept me from bonking at both of them and feeling pretty strong for the whole race.
An important fuel I often forget is sleep. Get a good amount of sleep before the race. I can never seem to do that - always too excited/nervous/FACTORe sleeping in the same room.