Getting light early in the day may help shift one's sleep cycle. If one does not have access to sunlight, one can invest in an artificial light source like a UV lamp or light box.
Avoiding caffeine at bedtime can have disruptive effects. One can try caffeine-free herbal teas as they promote sleepiness.
Another activity to avoid before bedtime is watching television or scrolling on your phone before bed. Complete darkness is optimal for sleep.
Physical exercises may help improve sleep cycle and quality. Even taking a walk can improve sleep quality.
Last but not least, reducing room temperature and making it cooler helps regulate the sleep cycle.