Good point about light
Orchidflower's post reminded me of something else I had read: to make sure that in the evening that no light is more than about 40W, and less is preferable. I think that may have a big impact for some people. I think that the light from the television also messes up my sleep.
Robert the Red has a good point that basically different things work for different people. And I've found that at different times different things work for me.
I'm glad to know that my experience with Melatonin sort of lines up with other peoples - that it doesn't "drug" me to sleep, that it doesn't always work, and that it is only one component (i.e. light, relaxation) in the equation of a good night's rest.