Sleep is central to all body functions. By the time you are 30 years old, you have already slept for about 10 years. The basis of good sleep is to maintain good sleep hygiene.
Dr Kevin Rosman from the Morningside Sleep Centre has this advice:
The sleep environment
The bed must be comfortable enough, the room quiet enough, dark enough, cool enough, and secure enough. Complete absence of sound would be the best, but is generally not possible. Second-best is a continuous quiet hum. Television is generally a bad idea. Sometimes double lining of the curtains may be necessary to keep the room dark enough. We sleep better at night when the environment is cool. If you have an air conditioner, for example, set the temperature to that which is comfortable for the "cooler" partner, and let the other simply add a blanket.
Winding down the brain
Before going to sleep, one needs to give the brain a chance to wind down. Allocate between 30 and 60 minutes for this. Going to bed directly after working or after exercise can cause difficulty getting to sleep. Caffeine and alcohol can affect sleep, and sufficient time should be allowed after the consumption of these before getting into bed.
Regular sleep habits
Because the body works on a number of different cycles, we sleep best at our usual bedtime. Getting up at the same time every day is also helpful.