The night time wash up is so very important, it's a 'must'.
First of all it makes sense to rid your face of the days accumulation of dirt, pollution, make up, etc. That's the washing part. A nice cleanser, milky for a drier skin or a gel for more active or oily types and plenty of water for a good rinse. Now is the 'best' time for some kind of treatment. In the day time our skin protects us, at night our skin repairs, so slather it on! A rich night time moisturizer, an AHA treatment lotion, Vitamin C serum or even I dare say some OTC product (over the counter). Just do something!
You will truly look better in the morning.