A toned Allison Williams has a denim moment in the December/January issue of harper by Harper’s Bazzar, which she guest edited. The Girls star wears a J.Crew top and Vince pants in a shot by Mark Abrahams for the cover, and inside she keeps it casual in looks from Zara, Express, Banana Republic, Uniqlo, and H&M. (harper is aimed at the “younger reader,” a.k.a. on a fashion budget.) She talks style and reveals who she admires to editor Tara Lamont-Djite. “When it comes to my style icons, I’ve always had a thing for the K’s: Keaton. Kelly. Kruger. Kate. Katharine,” she says. “They all represent sophisticated fashion that’s also full of life. After all, clothes are fun – it’s dress-up for adults. I’d like to call my style easy, timeless, and rustic preppy (if that’s a thing), which most often translates as endless button-downs, a chic pair of boots, a good variety of sweaters, and my staple – jeans.” She also shares a fashion tip for working out: “This is my gift to you: Spanx makes the most incredible exercise spandex,” Williams says. “I wear them almost every day. They have a little control top, so they’re flattering. I’ll often stay in exercise clothes all day, which I know is a faux pas.” You can get your hands on harper on November 24.