Drink your favorite caffeinated beverage (a Sobe energy drink is my weapon of choice) then take a nap right away with an alarm set for 15 mins. When you wake, the caffeine should be kicking in and you'll much more refreshed than if you just had the drink. Your mileage may vary, but it works well for me.
Are you a power napper? What are your crunch time tricks?
I know you have some, lx.