Frank Costanza had "Serenity now!" and Ralph Kramden had "Pins and needles, needles and pins, It's a happy man that grins" (not that either one worked all that well). What do you have? I have recently taken to quietly humming "America" (which is infinitely hummable, by the way) to myself when facing stressful situations and/or difficult-to-deal-with people. It works! Paul Simon - a self-help guru, who knew? Do you have a song or piece of music that works for you?