Prior to race day I try to eat a lot of food containing carbs the night before, refrain from alcohol, and get a good nights sleep. What usually happens though, is I go out, eat crap food, have a few to many drinks and only get about 5 hours sleep before dragging myself out of bed at the crack of dawn.
On race day my routine consists of emptying my bladder as soon as we arrive, unloading the bike and gear, & getting my nylons on. Amazingly my bladder has the ability to feel full again just before I need to go to the start line.