I find practicing mindfulness meditation using body scan helpful. If it doesn't work initially, I keep practicing over and over. Usually I fall asleep within 20 minutes or so.
http://www.mindfulnessinfo.com/exerc...scan-savasana/
Not to state the obvious but eliminate caffeine, alcohol, and heavy foods and vitamins for several hours prior to retiring for the evening. I also have a white noise machine to drown out distracting environmental noise. I’m sure others will have ideas that help for them also. Best to you.