Open your lips and fold your tongue towards your throat
Touch the tip of your tongue to your upper palate. Keep your upper and lower teeth together
Inhale deeply through the teeth with eyes open. Make a sound like (si-si-si) and feel the coolness at the back of your throat. Then close your lips and relax your tongue
Hold your breath as long as you can, with eyes closed
Exhale slowly through the nose without opening your mouth and feel the coolness of breath
Do this 15-20 times.