I'm sure there are a lot of different techniques but one I like to use is: http://restoremyposture.com/files/2012/01/MG_02151.jpg It might look silly but even when I've had Mountain Dew and can't sit still, I just turn off the lights, do this stretch, take deep breaths and I just about fall asleep (that's when I crawl into my bed). Worth a shot! It works for me.
A couple methods can be combined to help you get max sleep. They are: - no food or drink within an hour before bed - no electronics within an hour before bed - focus on nothing, if that's hard then on a black dot - I suggest no music unless it is music made to help you sleep, otherwise it distracts you - count as you breathe. In "one" out "two" in "one" out "two" etc.
Many doctors, psychologists and counselors recommend meditation as a way to place yourself in a mindset which is conducive, first, to relaxation, and then, to sleep. I practice an ancient form of meditation: prayer. In my case, I say a group of prayers which have been said in convents and monasteries (and, by lay practitioners such as i) for hundreds of years. It is known as Compline, and the first prayer I say is, "May the Lord Almighty grant me and those I love a peaceful night and a perfect end. Amen." and by the time I have said my prayers, I do, indeed, spend a peaceful night. Now, I'm not saying you must say Compline, or even pray. What I am suggesting is that you engage in mindful meditation before you settle yourself to sleep, peacefully.