" It just meant holding the lips together, teeth lightly touching, with your tongue on the roof of the mouth. Hold the head up perpendicular to the body and don’t kink the neck. When sitting or standing, the spine should form a J-shape—perfectly straight until it reaches the small of the back, where it naturally curves outward. While maintaining this posture, we should always breathe slowly through the nose into the abdomen. "

― James Nestor , Breath: The New Science of a Lost Art