It is very important to teach beginning students to relax and breathe properly. In the first few classes, focus on the deep Abdominal Breathing and make sure that they are doing it properly. While they are relaxing in Shavasana (Corpse Pose), ask each student to place one hand lightly on the abdomen. Before continuing on, check each person and gently move the hand onto the abdomen if necessary.
Make them practice Abdominal Breathing lying flat on the back, becoming aware of the breath, which should be slow and deep. As each person inhales, ask them to be aware that the abdomen is rising. As they exhale, the abdomen should sink down.
If a student is not breathing correctly, go to their side, place your hand on top of theirs (on their abdomen) and apply pressure downward as they exhale. Then ask them to inhale and release the pressure. Do this a few times until the student appears to know how to do this.
In the full Yogic Breath, inhalation happens in three stages. First, the diaphragm moves downwards into the abdomen, drawing air into the lowest part of the lungs. Then the intercostal muscles expand the ribcage and pull air into the middle part of the lungs. Lastly, air comes into the upper part of the chest. This is called clavicular breathing.
Ask students to sit in a cross-legged position and place one hand on the abdomen and the other on the chest. Inhaling slowly, feel the abdomen expand first, then the chest, and finally feel the air filling the upper chest. As they exhale, the air will leave the lower lung first, then the middle, and lastly the top part. This 'proper' breathing should be practiced on a regular basis. Make sure that students understand fully and are able to do this before continuing to pranayama.