It's safe to say that Diane von Furstenberg knows a thing or two about what makes a party-ready jumpsuit - the brand's founder was a regular at Studio 54, and her glamorous free-spirited style is at the heart of every collection. This piece is made from fluid black crepe with a plunging neckline that's framed with satin. It subtly pulls in at the waist before flaring out at the leg.