Ready for a 100 percent sass-on-a-stick styling trick? It's a bubbling-under mini trend we've spotted on the cool girl circuit, which has, like all new-to-your-fashion-radar things, got "you say tom-ay-to, I say tom-ah-to" potential. We're talking about lace-up detailing: those who worship at the altar of cool corsetry include French designer Isabel Marant (her cropped leather cigarette pants with ankle-to-hip side seam lacing are a seasonal staple in her collections), Christian Dior (whose Fall '14 collection, designed by Raf Simons, had a major lace-up focus — more on that later), and Love Moschino. So, getting tied up: what's in it for you? These style stalkers reveal all.