WHEN MARC JACOBS decided to improve his diet and exercise regimen three years ago, he also amped up his approach to grooming. The designer began getting regular facials, massages, manicures, and pedicures and now uses no fewer than five skin-care products a day. To finish, he applies Bang, his first new men’s fragrance in nearly a decade. “I was the anti­thesis of all of this,” the 47-year-old says of his newfound narcissism. “I just had no interest at all. And then it was, like, anything that makes me feel good I wanted more of. Taking care of myself makes me feel good.” Here are the highlights of his routine.