1. Set up a fixed schedule

First, reserve an interval of 7-8 hours for sleep. Lie down and wake up at the same time each day, even at weekends (when the gap should not be longer than an hour). In this way, your body will adapt to a steady pace. If you do not fall asleep in 20 minutes, get out of bed and do something relaxing: listen to some nice music, read a book or do some stretching exercises.