To begin 10-20 minutes, later 30-60 minutes
The eight levels of Self-Inquiry Meditation are described at the end of the eight exercise levels. Level 1/3 is focused on Awareness of the Unity of Body and Breath:
Feel your normal breathing and be conscious of the breathing process.
Be aware of the unity of body and breath. Feel and observe the expansion of the body with the inhalation and the contraction of the body with the exhalation.
Feel how the breath is not only taken in through the nose but also through the body. Feel how the flow of the breath streams through the whole body.