sleep
I'm lucky, I'm a sound sleeper - never have a problem once I'm actually in bed.
but I'm not so lucky in that I have a dog, who get me up at 6:30 - everyday...and I often do not go to bed until 12.
What I recommend: set you ebdroom up using feng shuei (sp?)
No television, cool colors, difused or no light. make the bed the ceterpiece of your room - the focus.
No caffeine after 6PM!
Regarding excersize: 30min to 60 min of vigorous activity, 3-5 times a week. You'll sleep like a baby!
Do not go over money (do you bills in the AM!), work, or emotional issues before bed. These tend to be high sources of stress, which can lead to insomnia.
Finally, although some recommend against it - a glass (or two) of wine, preferably red, full bodied, but mellow, with little tanic aftertaste. Alchohol is a depressant, and will get your body ready for sleep.