1-Always wash your face in the evening even if you were not wearing any makeup to wash off.
2-Staying hydrated will always help your skin stay healthier and therefor more clear.
3-Getting an appropriate amount of sleep, about 8 hours also gives your skin the time it needs to heal.
4-Changing your pillow case weekly will make sure there isn't an oily, germs build up rubbing against your face every night. As you can imagine that is not very good for your skin.