Sleep in complete darkness, or as close to it as possible. Even the tiniest bit of light in the room can disrupt your internal clock and your pineal gland's production of melatonin and serotonin. Even the tiniest glow from your clock radio could be interfering with your sleep. This will help decrease your risk of cancer. Close your bedroom door, and get rid of night-lights. Refrain from turning on any light at all during the night, even when getting up to go to the bathroom. Cover up your clock radio. Cover your windows—I recommend using blackout shades or drapes.