When we breathe through the L nostril, we connect with the R hemisphere of the brain, and shifts the nervous system into parasympathetic function. Try this whenever you feel you’re stressed out, anxious or you sense you’re in fight or flight response (all sympathetic nervous system activation).
Sit tall and place your R thumb up against your R nostril with your fingers pointing up.
Inhale and exhale slowly through L nostril, while making the exhalation a little longer than the inhalation.
Breathe like this for 3 minutes or more, then spend 30 seconds or a minute w/o your fingers manipulating your nostril, and continue the pranayama by focusing your attention on your nostrils – mental Left Nostril Breath. One way to keep the mind focused during both w/ and w/o finger tool, is to feel the coolness of the inhale and the warmth of the exhale.