Jessica Chastain, Cannes 2012BEImages; Wireimage; FameFlynet

Stylist Elizabeth Stewart had a big job this week—dressing Jessica Chastain for the Cannes Film Festival. “We have it down to a science,” the stylist told InStyle.com of the process at the ninth annual PS Arts fundraiser in Beverly Hills this week. “We’ve planned everything out beforehand. It’s like a military operation. We photograph everything. We send a PDF. There’s a printed and e-mailed copy. It’s pretty organized.” As for how she got her hands on so many beautiful gowns—Armani, Dolce & Gabbana, Alexander McQueen included—it’s also very methodical. “When you dress a girl like that, you have the world at your fingertips,” said Stewart. “Everybody wants to dress her.” See Stewart’s Cannes fashion show for Jessica Chastain in the gallery.

— Violet Gaynor and Lindzi Scharf