If you give any kind of a shit about makeup and you're not doing this already - start. If you never want to hear the phrase, "Woah, you look tired again," then this maneuver is heavenly.
(Also, if you're a mutant who say things like that? Man. You're really the worst. I mean that sincerely. It's one of the silliest things you can say to another adult. Absolutely moronic.)
I guess you could use a white powder, but that might be too loosey-goosey. I use the $5 white eyeliner pencil (it's less pencil-y, more gel-like) from Sephora's own collection.
You can find it along that horrible look-at-these-products-while-you-wait-to-leave line before you buy something.