Dr. Andrew Weil may have the solution to the countless sleepless nights. If you have this problem, you should try this trick which will put you to sleep in seconds.
Yoga and its breathing practices inspired Dr. Weil to produce "The 4-7-8 Breathing Exercise". Dr. Weil describes that this exercise is very simple and can be completed anywhere. Also, it won't take long and you don't need any equipment.
Here are his written instructions:
1) Exhale completely through your mouth, making a whoosh sound.
2) Close your mouth and inhale quietly through your nose to a mental count of four.
3) Hold your breath for a count of seven.
4) Exhale completely through your mouth, making a whoosh sound to a count of eight.
5) This is one breath. Now inhale again and repeat the cycle three more times for a total of four breaths.
This breathing exercise is supposed to lower the heart pulse and calm the mind. Dr. Weil advises you to focus on keeping the ratio correct and inhaling/exhaling deeply every time.
Maybe it sounds too easy to work, but don't criticize it before trying it.