Let Breath be the Boss
The way you breathe directly affects body and mind. Conversely, the state of your body and mind affects the way you breathe. Just imagine watching a suspenseful movie, practically holding your breath until the drama dies down, and then you let out a sigh of relief. Right there your anxious mind is telling the breath what to do. Now imagine using that knowledge to reserve engineer a stressful scenario. Your mind is frazzled, fists clenched, about to say or do something regrettable, rather than letting emotion or stress dictate the scenario, let your breath be the boss.
Take a long, slow deep breath in, hold the breath for as long as feels comfortable, then let out a slow, full breath out. Repeat this for 10-12 breaths and observe any shifts in your physical or mental state.
By taking longer and slower breaths, stretching approximately 6 seconds for both inhale and exhale you can shift your nervous system from a state of stress (sympathetic nervous system) to a state of rest (parasympathetic nervous system). The wisdom of the yogis, as well as modern researchers show that it only takes 10-12 of these breaths to make the shift.