Sleep is one of the most important things you do for your health, yet most adults in modern societies are chronically underslept. The science of sleep hygiene has identified specific habits that reliably improve both the ease of falling asleep and the quality of sleep achieved.

The ten habits

1. Consistent wake time. Getting up at the same time every day — including weekends — is the single most powerful sleep hygiene intervention. It anchors your circadian rhythm. The wake time is more important than the bedtime.

2. Avoid caffeine after 2pm. Caffeine has a half-life of 5-7 hours. An afternoon coffee at 3pm leaves half its caffeine in your system at 9pm. Even if you fall asleep, caffeine reduces deep sleep quality.

3. Dim lights 60-90 minutes before bed. Bright blue-spectrum light suppresses melatonin production. Use warm, dim lighting in the evening. Enable night mode on screens or use blue-light filtering glasses.

4. Cool your bedroom. The optimal sleep temperature is 16-19°C (60-67°F). Body temperature drops during sleep onset — a cool room facilitates this. Open a window if possible.

5. Avoid alcohol near bedtime. Alcohol helps you fall asleep but significantly disrupts sleep quality, particularly REM sleep. Even moderate amounts reduce overall sleep restoration.

6. No screens in bed. Keep the bed associated only with sleep (and sex). Working or watching content in bed trains your brain to be alert there, not sleepy.

7. A wind-down routine. The same 20-30 minute sequence each evening — shower, reading, light stretching — signals to your nervous system that sleep is approaching. Predictability helps.

8. Write tomorrow's to-do list. One study found that writing a to-do list for the following day before bed reduced the time to fall asleep significantly, by offloading rumination onto paper.

9. Regular exercise — but not too late. Regular exercise improves sleep quality substantially. However, vigorous exercise within 2-3 hours of bedtime can delay sleep onset due to elevated core temperature and adrenaline.

10. Get morning light exposure. Bright light in the first 30 minutes after waking anchors your circadian rhythm and improves evening sleepiness. Even on an overcast day, outdoor light is 10-50× brighter than indoor lighting.