You know the old adage: You've only got one chance to make a first impression. Well, that holds especially true on a first date with a new guy. Mad Men costume designer Janie Bryant recommends wearing something "sexy, flirty, and fun." Designer Marc Bouwer — who's newest collection will debut at New York Fashion Week and Feb. 11 at 10 p.m. EST — suggests not dressing too provocatively, though. "Don't be afraid to show off your shape, just not in a very low-cut or bondage look," he says. "I suggest a button down silk shirt paired with a pencil skirt or a sexy pair of jeans."