What type of job do you have. What I am getting at is that if your job or day does not consist of much exercise that could be a key element. a good old fashion workout or hard labor can help you sleep.

Some people meditate:
http://www.dreamviews.com/forum/viewtopic.php?t=3908

You could have anxiety. I myself have suffered from this problem where my mind races before I go to sleep

Melotonin maybe. Calm tabs, Valarian root.

A typical sleep pattern. One that does not change constantly.