Some days, you need some help looking "bright eyed and bushy-tailed." This is when makeup can do its best work. It can make you look alert, awake, and neat when you feel the least bit like any of these things. Benefit Eye Bright ($18) is one of these such tools. It's a light pink colored pencil that hides the dark coloring that can creep up underneath tired eyes. Just slick a little bit over your dark circles and blend just a bit (on light-skinned gals like me, there's hardly much blending needed at all) and your eyes look instantly much more awake.
You can also dab a bit right in the inner corners of your eyes, near you tear ducts, for a nice brightening effect, or just under the arch of your eyebrows for an instantly more groomed look and to add a bit of depth to your eye shadow job (Benefit sells a separate brow highlighting pencil, also $18, but they really seem like the same thing to me).
So, while you really *should* be getting a good 8-9 hours of sleep a night, we all know that on occasion that is just not quite possible. On those days, Eye Bright is your friend.