When you think of a true It-girl, like Alexa Chung or Chloë Sevigny, you probably realize that what they're masters at is wearing things no one else will have. Gals like these have such a distinct sense of personal style, they won't be rolling up to an event — or even lunch with a friend — wearing Zara or ASOS (no matter how on-trend and irresistible those fast fashion retailers' wares are). Instead, you'll be dying to know where whatever they're wearing is from, and yet know that you probably A) Can't afford it, or B) Can't get it because, well, it's vintage.