You cannot truly get 8 hours of sleep in 4 hours
Use a consistent sleep schedule every day
Go to bed and wake up at the same time
Keep your bedroom dark, quiet, and cool
Avoid caffeine for 6 to 8 hours before bed
Avoid alcohol before sleep
Stop using screens 1 hour before bed
Do a short wind-down routine before sleeping
Keep naps short or avoid them late in the day
Exercise regularly, but not right before bed
Reduce stress before bedtime
If you only have 4 hours, prioritize uninterrupted sleep
If you feel constantly tired, see a doctor