Calculate optimal bedtimes and wake-up times based on 90-minute sleep cycles. Wake between cycles and feel energized.
Keep bedroom between 60-67°F (15-19°C). Cooler temperatures promote deeper sleep.
Avoid blue light 1 hour before bed. Use night mode or blue-light glasses.
Stop caffeine 6+ hours before bed. It has a half-life of ~5 hours.
Go to bed and wake up at the same time daily, even on weekends.