Lock into the underlying “Hum” of Creation, of Life Force. As you notice the very fine/subtle sensations, you will begin to experience the body as a contortion of energy, both moving and with potential to move. The mind then goes deeply into an interiorized trance, a meditation on the Life Force, the Current of Bliss!
As you feel and tune into the underlying vibration/hum that is at the root/foundation of awareness, the body contorts…and the mind/consciousness is then cognizant of both surface distractions and “goings ons” as well as with the deeper, “subterranean” echoes and reverberations, the sublime “Hum” of Creation.
Such fine/subtle sensations, bubbles of vibrations and sensations of coolness, warmth, subtleties of the incoming and outgoing breath. You can explore to infinite depths the incoming and outgoing breath!