According to experts, one of the keys to having good quality sleep is maintaining good sleep hygiene which basically means improving your habits and environment. Here are some easy tips to help. Avoid frightening movies or disturbing content online before falling asleep.
Steer clear of caffeinated drinks if you know that caffeine agitates you easily.
Maintaining a good temperature in the bedroom (not too hot and not too cold) and use the bed only to sleep in.
Make sure your mind and body are already relaxed, so do not work until too late or do not study until just before going asleep.
For time difference problems gradually change the time to go asleep and to get up as the more you worry about not being able to fall asleep the harder it can become.
Find out what makes you feeling relaxed and what not. Find out if there are specific disorders that disturb your sleep.