Get plenty of sleep before you start up. If nerves or noise keep you from sleeping, just lie there and rest your body. There is absolutely no need to start at midnight or 2:00 AM. If you are that slow, you probably won't make the summit anyway. Get some rest and don't start up before 3:00 or 4:00.
I just want to scream when well-meaning people say, "climb high, sleep low" and then recommend sleeping in Lone Pine. You need to acclimatize. To do that, you need to hike AND sleep as high as your body will allow for as long as your schedule will allow. The best sleeping altitude is the highest altitude at which you don't get sick. I'm 31 and 0 on Whitney, and I always sleep at the portal (if the road is open).
