You are supposed to sleep over 7 hours a night, if you don't your skin is less tonic, less smooth and your complexion can get a bit duller.
To help fighting the effect, select a rich and thick night cream (thicker then your day cream) and, before putting it on, cleanse your skin, rinse it and, if you do have one put on serum.
Try to avoid your under eye area with the night cream, not to overload it, than use an appropriate eye care contour cream.
Use cleansing oil to clean your face at night, it is very easy to get all the little extra make up off and I feel my skin looks better of in the morning.
Once more, I remind you that my favorite part about skincare is to activate the microcirculation by massaging the products in circular motions within your skin. This as well as the use of shower oils is just lovely to feel on the skin.
Mask up! You have so many masks around, it might be confusing at times. My best advice would be to stand in front of a mirror, see what your skin is like and get the answer treatment: dry, oily, mixte, acne-prone or aged. You will get a fast treatment for your skin and it will regenerate directly after it, while you are asleep.