I'm the opposite of a lot of folks here. I can fall asleep quite easily, but my mind starts racing with the negative crap the moment I wake up.
I have found Yoga to be the best way to empty your mind so you can rest or sleep. There are various schools of Yoga that accomplish various things. Find a Yoga class that deals specifically with controlling the mind. If Yoga classes aren't advertised in your area, see if there is a Buddhist Temple or local Buddhist group that can guide you.
I really do not know how many times I have suggested memorizing the 23rd Psalm and mentally repeating slowly it during those times when sleep is evasive but everyone who has taken that suggestion has reported back some very positive results. It has a calming effect and it blocks out any other wayward thoughts that might keep one awake. Personally, I have never had to repeat the Psalm more than twice before sleep takes over and for me, when the dreams come, they seem to be very calm also.