Linda Evangelista brushes her brows up and then down before she starts filling. Julianne Moore is adamant about an ashy brown set that's perfectly straight. For Gucci's Hollywood friends and clients, face-framing arches involve an arsenal of tricks honed over a lifetime on camera. As for her own set? "When I don't have my brows, I feel naked, "she says of her sworn fattening and lengthening quick fix. In today's tutorial, she reveals the two-pencil technique that completely changes her face. "I'm going to make clean brow products, don't you guys worry," she says as she alternates between adding all-over heft, then drawing in the illusion of "tiny bitty" individual hairs with a pair of black and espresso pencils by Chanel and Tom Ford, respectively. Pausing between brows to assess her work, she admits that the perfect touch-up evolves with each decade—meaning the subtly arched silhouette you lived for at 20 may give way to a flattering round or linear shape at 40. The only rules? No plucking and no rushing. Just few extra minutes is better than microblading or brow extensions.