Put on music and dance, scrub the bathtub spotless, whatever engrosses you—for at least 10 minutes. "That's about the minimum time needed to break a cycle of thoughts," says Nolen-Hoeksema, who's been studying rumination for more than 20 years. Or choose something to focus on. "A friend told me that she once started counting the number of times the speaker at her conference said 'like,'" Nolen-Hoeksema recalls. "By the time he finished, she'd stopped ruminating."