Fold the tongue so that tip of the tongue might touch the upper palate and draw air through the mouth with a hissing sound C C C C (or Si, Si, Si, Si,). Then retain the breath as long as you can without feeling suffocated and then exhale slowly through both the nostrils. You can keep the two rows of teeth in contact and then inhale air through the mouth as before.The practice enhances the beauty of practitioner and vigour of his body. It removes hunger, thirst, indolence and sleep. When you are thirsty, practice this and you will be relieved of thirst immediately.
Now half the process is over, draw air through the right nostril. Retain air as before and exhale it slowly through the left nostril. All these six processes constitute one Pranayama. Do 20 in the morning and 20 in the evening. Then gradually increase the number. Have a mental attitude that all the divine qualities, e.g., mercy, love, forgiveness, joy, etc. Entering the system with inspired air and all bad qualities like lust, anger, greed, etc. Are thrown with the air expired. This Pranayama suppresses all diseases, purifies the Nadis, puts the spirit of concentration, improves digestion, increases digestive fire and appetite, helps maintain Brahmacharya and awakens the Kundalini sleeping in Muladhara. Purification of Nadis occurs rapidly. You will also have levitation (passing over the ground).
In the early morning, answer the calls of nature and sit for the practice. Practice Pranayama in a dry well-ventilated room. Pranayama requires deep concentration and attention. It is always better to have the practice in a steady posture. Do not keep anyone by your side to avoid distraction of your mind.
Before you sit for Pranayama, thoroughly clean the nostrils well. You can take a small quantity of fruit-juice or a small cup of milk or coffee even before the practice. When you finish the practice take a cup of milk or something light to eat after 10 minutes.
Practice only in the morning during summer. If there is heat in the brain or head, apply Amla oil or butter on the head before you take your bath. Take Misri Sharbat by dissolving sugar candy in water. This will cool your whole system. Do Sitali Pranayama also. You will not be affected by the heat.