• Maintain a regular bed and wake schedule, including on weekends. A
  regular waking time in the morning helps to set your body’s circadian
  rhythm, making it easier to fall to sleep at night.
• Establish a regular, relaxing bedtime routine. Avoid exposure to bright
  light or stimulating activities before bed. You may want to try a warm
  bath with 1 or 2 cups of Epsom salts before getting in bed.
• Use your bedroom only for sleep and sex. Remove computers, televisions
  and you may even need to remove your clock if it distracts you from
  sleep.
• Do not spend too much time awake in bed. If you are not sleeping, get out of bed and do something else for a while.
• Finish eating at least 2 to 3 hours before your regular bed time,
  especially if you experience heartburn. You may also need to restrict
  fluids, though some people find milk or herbal tea soothing and helpful
  for falling to sleep. If hypoglycemia is an underlying cause of your
  insomnia, eat a small snack containing protein before going to bed.
• Create a sleep-promoting environment that is quiet, dark, comfortable
  and cool. Wear an eye mask if the morning light wakes you. Use ear
  plugs if noises bother you.
• Sleep on a
  comfortable mattress and pillows. Make sure your mattress is supportive
  and that it has not exceeded its life expectancy of about 10 years.
  Make sure to choose bedding free of allergens and make the bedroom
  inviting for sleep.
• Try a sleep CD or listen to calming music after lying down.
  (www.sound-remedies.com)
• Avoid naps, particularly in the late afternoon or evening.
• Avoid caffeine within 6-8 hours of bedtime. The stimulating affect can
  change the quality of your sleep. Green tea is a better choice but
  avoid it later in the day.
• Avoid alcohol and
  nicotine, especially late in the day. Although some people think
  alcohol helps with sleep, it actually disrupts sleep and leads to more
  nighttime awakenings.
• Exercise regularly. It is best to complete your exercise at least three hours before bedtime.

References: National Sleep Foundation