Whenever I have a hard time falling asleep at night, I* play a game. The game is distracting but also simple enough to let my mind calm down so that I can fall asleep.
It goes like this ... you pick a subject and must name items in alphabetical order.
For example, if you pick the subject: fruit
until you get to letter Z, or fall asleep, which ever comes first.
So far subjects that I've used include:
things you find at the swimming pool
things you find in/on an airplane
items I've seen in TV commercials
You can determine just how picky you are about the rules ("Red apple" is/is not a fruit) since the goal is to fall asleep, not actually come up with correct items.
*The game also works with your bed partner, just take turns naming items.
This game has been a handy thing to have, and it works every time.