Natural breathing is a technique that is used before pranayama to relax the body and mind. With natural breathing you are not controlling your breath. Your breathing should just be natural.
As always, get yourself into a comfortable sitting position with your back straight. Hands can rest (palms up or down) on your thighs. All breathing is through the nose. Try to keep your eyes closed and stay still throughout.
You will be taking your awareness to different parts of the body. As you become aware of each body part, ask yourself if it’s tense or stressed. if it is, just let it relax and be heavy, and let gravity do the work.
Don’t dwell too much on any specific part of the body, spend just a few seconds on each body part and then move on.
Technique
Take your awareness to your right hand, and to the thumb of the right hand. Move on to the index finger, middle finger, third finger, and the small finger, all of the right hand, the right forearm, upper arm, and shoulder. Take your awareness from your shoulder to your hip, down the right leg to the knee, and down to the right ankle. Move your attention to the right foot and then all of the individual toes in turn.
Repeat the above on the left side, starting with the left hand and finishing at the toes of the left foot.
Now move your attention to the base of your spine. Slowly work your way up the back to the lower back, middle back and then upper back.
Move your awareness from the top of the back to the base of the skull, over the top of the head to the crown. Then move your awareness to the forehead, eyebrows, eyes, cheeks, and mouth.
Next take your awareness to the tip of your noes. Observe the air going in and coming out as you inhale and exhale. Try to notice any change in temperature. Maybe the air is cooler when inhaling compared to exhaling. Also try to notice any sound as the air flows in and out, and any movement in the chest or abdomen.
Finally, sit for a couple of minutes and just breathe naturally. Don’t try to stop yourself thinking. Simply observe any thoughts that may come into your head objectively and passively. Don’t get involved with them, just watch them as they enter your consciousness and then leave.