The TIPP Method
The TIPP Method stands for Temperature, Intensive exercise, Paced breathing, and Progressive muscle relaxation. Doing one or more of these steps can help regulate anger. They don't have to be in any sort of order.
Temperature
What to do: Take a cold shower, put an ice cube or ice pack on your skin, or other similar cold-shock to your system. Why/how does it work? The aggressive cold can be a shock to your system and turn focus from inside your mind (angry) to outside your mind (not so angry).
Intensive exercise
What do do: Walk briskly or jog, ride a bike, swim laps, jump rope or do jumping jacks for about 15 minutes. Why/how does it work? When you make your body move your brain releases feel-good chemichals called endorphins.
Alternatives: Thrash around like a worm or fish to angry music for a minute or two.
Paced breathing
What to do: Inhale through nose for four counts, hold for seven counts, exhale through mouth for eight counts, repeat. Why/how does it work? This increases your oxygen intake and forces your heart to stop beating so fast.
Alternatives: Breathe in the box method (4-4-4-4), don't count but just make each exhale longer than each inhale.
Progressive muscle relaxation
What to do: Sit or lie in a comfortable position, tense muscles in your feet really hard, then relax. Work your way up your body from feet to face. Why/how does it work? Tensing your muscles signals to your brain "!!!", then forcing them to relax tells your brain "ok, we're good now."
Alternatives: Bite a pillow or stuffie, strangle pillow or stuffie. Really anything that tenses muscles, then forcibly relax.