Though I'm a reasonably ambidextrous leftie, after almost a year and a half with a straight, I still shave only with my dominant left hand, so far with mostly equal results on both sides if I'm stretching and paying attention. It's weird, though-I throw a ball, cast a fly-rod, shoot a pistol, swing a golf club, and pick a guitar right-handed, but I shave, write, and shoot a rifle southpaw.