Eight bedtime practices with real research behind them, in priority order. Fixing the first one or two usually produces the largest gains; work down the list only if those don't solve it.

1. Fixed bedtime and wake time. The single most important signal to circadian rhythm. Within 30 minutes daily, weekends included.
2. No caffeine after 2 PM. Half-life 5-6 hours; 3 PM coffee still affects you at 10 PM whether you feel it or not.
3. Cool bedroom (65-68°F / 18-20°C). Core body temperature needs to drop for sleep onset; a warm room fights the biology.
4. Dark bedroom. Blackout curtains if needed. Light exposure fragments sleep architecture even through closed eyelids.
5. No screens 60 minutes before bed. Blue light suppresses melatonin; content stimulates the brain. Two separate problems, same solution.
6. Consistent wind-down routine. 15-30 minutes of low-stimulation activity in the same order each night. Signals "sleep coming" to the nervous system.
7. Finish eating 2-3 hours before bed. Digestion disrupts sleep architecture; acid reflux rises when lying flat soon after eating.
8. Alcohol earlier, not near bedtime. Alcohol knocks you out but fragments the second half of sleep. If you drink, finish 3+ hours before bed.

Eight practices. Fix 1-3 and most sleep complaints resolve within 2 weeks. If they don't, the remaining five cover almost everything else. Chronic insomnia that survives all eight is worth a doctor's visit — sleep apnea, depression, and anxiety each produce sleep problems that lifestyle changes can't solve alone.