Single Nostril Breathing

The object of practicing Yogic breath discipline, or "Pranayama", is to increase physical and mental health. You can practice the breathing exercises on their own or integrate them into your program of Yoga Asanas. Sit comfortably in a cross-legged position, with your spine and neck straight, but not tense.
Hold your head erect and gently close your eyes. Use the fingers of the right hand to close off each nostril in turn. Hold them in a position called "Vishnu Mudra". For "Vishnu Mudra", extend the thumb, ring finger, and little finger of your right hand and fold down your other two fingers into your palm. Rest the left hand on your left knee.

Breathe through the left nostril. Close right nostril with thumb, and inhale through left nostril to a count of four. Exhale to a count of eight. Repeat 10 times. Breathe through the right nostril. Close left nostril with the two end fingers, and inhale through right nostril to a count of four. Exhale to a count of eight. Repeat 10 times