Good sleep hygiene . Is very important. 1. Keep a regular bedtime & wakening time (to include weekends). Get up the same time each day, regardless of what time you fell asleep. 2. Make a regular, relaxing bedtime routine. Relaxing rituals prior to bedtime may include a warm bath or shower, aromatherapy, reading, or listening to gentle music. 3. Sleep in a dark, quiet, cool room on comfortable mattress & pillows. 4. >.
Several, but. It's best to first determine why you're having trouble with your sleep. Are you following good sleep hygiene -- consistent bedtime & waking; cool, quiet, dark sleeping room; no caffeine after 12 noon; no alcohol (disrupts sleep cycle); regular exercise (not at night) etc? Chronic insomnia needs workup w/doctor. Temporary help = chamomile tea, valerian supplements, melatonin; kava; hops, etc.
Valerian . Health food stores commonly have this. Make a tea. It tastes terrible so honey and spices are useful.