Dreams & Second Sleep
Day Light & Dark Night
We sleep in two phases.
Our sleep is divided into two halves, depending on the person, your pattern may differ. Mine is to sleep for three hours, then sleep for another five hours.
One of my best friends, Jane Carleton, is a dream expert, here is one of her letters to me.
I didn't realize you have had frequent trouble sleeping! I'm sorry!
Did you know that research shows the habit of sleeping 8 hours is fairly recent, and that for eons the usual sleep pattern was to have two periods of sleep in the night, punctuated by a period of rest or quiet activity in between? There are many historical references to the "first sleep" and the "second sleep" as the norm. Check out this article...it's very interesting. http://www.bbc.com/news/magazine-16964783
I do not go on the computer for at least an hour or two before bed. I don't check emails on my phone, etc. It is too stimulating...one reason:
Research also shows we have two biological rhythms regulating sleep and wakefulness. There is an upsurge of one of these cycles in most people around 9:00pm and if you let yourself get activated by stimulus at that time, it will charge up. . If you don't, the cycle will remain more dormant.
A fabulous book about sleep in by sleep researcher William Dement, MD, "The Promise of Sleep", http://www.amazon.com/Promise-Sleep-Medicine-Connection-Happiness/dp/0440509017/ref=sr_1_1?s=books&ie=UTF8&qid=1406758024&sr=1-1&keywords=william+dement
Another idea is to not watch TV in bed before trying to sleep. Same reason. Make bedtime all about rest, peace, reading, and being deliciously cozy. Don't do work in your bedroom either. Make it a sanctuary, not a place of thinking, planning, etc...
It takes about a month to create a new habit; you know that.
Reading in bed always makes me sleepy.
If you can't fall asleep, don't fight it...use that time to play in the hypnogogic zone, a highly creative state, a thin layer of consciousness between being awake and falling asleep. It's a place that creative people have used to great success to find inspiration. Artists have been inspired by the visual nature of this zone. Lie comfortably and watch the squiggly lines, etc., just be present with what shows up...ideas, word, visions, bodily sensations. Don't force anything. If a to-do list shows up, use your meditation skills to move those thoughts on and go back to breathing and resting in the zone. This is a tool people who want to learn to do lucid dreaming and Tibetan lamas play with. The idea is to be present and to try to sustain this zone. It's not quite asleep and not quite awake.
I've also used a CD created to help support delta (the deepest) sleep: Delta Sleep System. You can listen to it here: https://www.youtube.com/watch?v=kqJbJHS2Rf4 It's meant to entrain the brain waves into deep sleep mode.
Love Jane 
Circadian Response Curve, blue light can keep you awake.
Use amber or red night lights so that at bedtime, or if you get up in the night, you will not trigger the 'wake up' circadian response with blue lights.
The sun plays an important role in our wake and sleep cycles, known as your Circadian Rhythm. See Circadian System for more information.
Dreams - You Decide the Ending
We all have experienced upsetting dreams, some more intensely than others.
Did you know you can write your own ending to your dreams?
For more advice on dreams, dreaming, and taming your scary dreams,
visit Your Dreaming Self. Jane E. Carleton, MA, GG
Jane and Tiger, taming your scary dreams - http://www.yourdreamingself.com/