Take a long hot steamy shower, or soak in a hot bath for thirty minutes right before going to bed.
Follow with a cup or glass of heated homogenized milk.
Lower the temperature (if possible) to high 60's.
If you live in the country or suburbs where there is grass & trees, open a window (will allow greater fresh oxygen supply to breathe).
Obviously, any CNS stimulants (or...obversely...quitting any CNS stimulants) will interfere with sleep.
When in bed, read one chapter/day of a good book...(or as a last resort...get in bed and read What Is To Be Done by Vladimir Lenin -- it's guaranteed to make you fall asleep...I'm actually not kidding)
If possible, to walk at least one mile each day until you're getting tired.
If all else fails, call Drew Barrymore.