11/18/2010 12:23 pm ET | Updated May 25, 2011

How To Conquer Lanvin x H&M And Get Everything You Want

Lanvinmania hits H&M this Saturday morning, and if you're in New York and want to get your hands on any of it, it's time to start planning.

In case you weren't already laundering your leggings and bodysuits in preparation for mid-store quick changes, here's the lowdown on how you'll actually be able to snag that ruffle-shouldered dress and wear it out that very night: