Hey!
Great question, the most important thing when it comes to sleep is to make sure you're well hydrated, you have not eaten anything that is hard to digest before bed, you haven't consumed any mind-altering substances and of course, having the same sleep-cycle every time. People who work shifts, ie. they work one week days and other week nights, then it is really hard to get good sleep - leaving you sleep deprived. Also, sleep is altered if you have stress or anxiety. You can also use medications to fall asleep more easily, but keep in mind that you might become dependant on those, and you may not fall asleep without them. Consult with your family care phycician or main care doctor with your issues.