alternate nostril breathing
balancing, calming, anti-anxiety, and very relaxing

Place the right hand in Vishnu Mudra (forefinger and middle finger bent towards the palm; thumb, ring, and pinkie in the air). To do one round: close off right nostril with the thumb and inhale into the left nostril; close left nostril with ring and pinkie fingers, open the right nostril and exhale through the right, then inhale into the right nostril; close the right nostril, open the left, and exhale through the left nostril. Continue, doing 5-20 rounds.