The holiday season is the perfect time of the year to really prove our sartorial chops. But where's the line between cool and costume? How can one pull off Grandma's vintage tiara without looking like Honey Boo Boo? Stress no more — we're here to help you master the holiday's trickiest fashion trends. Ahead, how to wear velvet, glitter, winter white, and more...without looking like your own Nightmare Before Christmas.