Feeling tired once in a while is fine during to our lifestyle. But if it is a serious problem then one should seek necessary medical help. I have few tips one can follow to get better sleep.
Avoid watching TV in the evenings especially the kind of shows which activate the mind like voilence, drama etc
Do not drink coffee / Tea after 4 in the evening
Drink a glass of warm milk before going bed.
Some times body temperature also disturbs the sleep. washing your face, palm and feet in cold water helps to fall asleep easily.
Try meditating at least 30 min in the late evening preferably before dinner.
There should be at least 2 hrs gap between dinner and sleep time.