Every year, the hottest A-listers flock to New York's Metropolitan Museum for the annual Met Gala ball. It's a super-fashionable affair (hosted by none other than Anna Wintour) so let past guests Blake Lively, Cara Delevingne and Alexa Chung give you a whirlwind education in how to pose like you're on a red carpet. You never know when it might come in handy ; )