I know from experience how exasperating it is to lay down and not go to sleep for an endless number of hours. However, you can control that. Some people need a lot of sleep and some can do without much. What kind are you? I found out that if I go to sleep after midnight and wake up very early, I am at my most fresh. Since I wake up early, I am also usually so tired by the time I get to bed that I can go to sleep almost immediately.
Also try not to take naps during the day because they make you fresh and that you do not want if you want to go to sleep easily. Also, while physical activity does make you tired, you are truly tired enough to sleep by mental exercise. Every night when you retire to bed, pick up a challenging book until you start to droop. Do the daily crossword puzzle every night in bed and I am sure you would be quite sleepy even before you can finish it. Some people also find listening to soothing music useful in making them drowsy and sleep peacefully. You may also try to get involved in some fiction. Start thinking up a story. Revise it every night and add more to it every night before you drift off to sleep. Maybe one day, your anti-insomnia fiction would make a bestseller paperback! Counting sheep is an old exercise and I think it is too redundant to tire me out enough. But try it out for yourself to see if this ancient remedy helps you.
Try a cup of chamomile tea or a cup of warm milk before bed. These help boost the chemicals in our brain that signal relaxation. A warm leisurely bath also helps.
Get a glass of milk and put it in the microwave for 10-15 seconds
turn off all lights
when your in your bed and cold that usually means your tired