This involves the use of the abdomen, chest and clavicular region. It can also be practiced before other breathing techniques. It allows one to have maximum inhalation and exhalation. It can be combined with deep breathing (using a ratio).
Inhale slowly, allowing the abdomen to rise. When the abdomen had expanded as much as it can allow the chest to expand outward and upward. Once the ribs have expanded as much as they can inhale a little more so that the collar bones move up slightly. Then slowly exhale first allowing the collar bones to move downward, then the chest and finally the abdomen. Continue the practice without any strain, jerks or tension. The breath should feel natural and after some time it should be mostly thoracic and abdominal breathing. Abdominal breathing should be at least 70% of the breath.
Breathwork India 