Business on one sideparty on the other. Cotillard's hairstylist Robert Vetica used the grunge era as a muse to create her textured updo. "Our inspiration also came from her dress," Vetica told us. "It looks like two dresses in one, so I wanted to carry that feeling with brushed-out finger waves, a deep side part, and the sleek texture on the side." He prepped her strands using Rene Furterer's Volumea Volumizing Foam ($23; beauty.com) to add body, and after forming the soft wave, the Vegetal Finishing Spray ($27; beauty.com) kept the style in place. A spritz of Rene Furterer's Glossing Spray ($23; beauty.com) gave Cotillard's updo a mirror-like shine. Her fresh-faced makeup, created by Christophe Danchaud, was kept natural and is one of the few looks from the night that can be worn off the red carpet. "It's simple," said Danchaud, who used Koh Gen Do products. "The look is very feminine and soft, which can be worn for both day and night."