If leaving it to the last minute is your specialty, then we've got a Halloween fix you can't say no to (literally —at this point, you've got no choice). Actress Ashley Madekwe nailed trick-or-treat dressing in a helluva (sorry, we had to) joker get-up and the good news is it's super easy to replicate. Pair a belted white dress with a white hat and some white sneakers. Chanel bag, optional. Just add green hairspray and red lip for an extra side of horror.