Sleep as much as you possibly can! I cannot emphasize that enough. Sleeping pills or not, just make sure you're sleeping. I say this because sleep is the difference between functional mania and "I've checked into the Twilight Zone" mania for me.

During the daytime, try to expend as much energy as you can. Go for a walk. Exercise. Go on a cleaning binge. Pick up a new hobby you've always wanted to. Try to harness all that energy in a productive, safe way. Distractibility does get to be an issue at times with this, but I find it's better than trying to sit still.