Concealer. I don't care who you are, if you are over 25, you DO have shadows whether you know it or not. A little concealer under the eyes really wakes you up and makes you look younger and less tired. The skin around the eyes is so thin and thins more with age. Then you see the little veins which come through as dark circles.

I would leave the house completely barefaced (and have lots of times) but never without a bit of concealer around my eyes to assure people don't think I'm a zombie.