To calm red skin under your mustache, slather on moisturizer or aftershave balm (for dry skin) or toner (for oily skin). You can also use conditioner—yes, the same kind you put on your hair—to keep the mustache soft, as long you rinse it out thoroughly. As for taming rogue strands, mustache combs are 1970s relics. Try smoothing on a pinhead-size amount of beard wax, like Clubman Moustache Wax (regular hair pomade works too). Or do nothing at all—a three-week-old mustache shouldn't be too unruly. But be sure to closely shave the rest of your face every day--use pre-shave oil, thick cream, and a badger brush to prevent irritation—so you look like a guy with a defined mustache, not one who just came off a bender.