As someone else said, when you wake up, get up. Don't linger in bed. Take three deep, invigorating breaths.
Meditate twice a day. I find I need less sleep when I meditate regularly for at least two 30-minute periods.
Exercise regularly in the morning. I like to take a long walk.
Eat a big breakfast, medium lunch, and small simple dinner.
Don't eat during the three/four hours before bed.
Don't use a computer or bright screen for 30 mins before bed.
Use a program like Flux that changes the hue of your monitor after sunset so you aren't looking at daytime blue colors when you're trying to unwind.
I've found metta meditation while trying to fall asleep helps me sleep quickly and rest well. Doing this, I haven't had a nightmare in a very long time.
And honestly, I think a lot of the fatigue of our times is caused by monkey mind gone wild with gadgets, endless internet surfing, and entertainment at every turn. If you can simplify your activities in general, it may help you feel less tired mentally and need less sleep.
Also if you're trying to reset to a new wakeup time, I've found skipping dinner the night before and fasting until breakfast helps me get used to the new wakeup time in a day or two instead of a week. This works really great for jet lag.
The power of buddha-dharma is revealed depending on whether or not there is effort, and is distinguished depending on whether or not it is practiced. - Dogen, "Guidelines for Studying the Way"
Namu Amida Butsu