When focusing the mind in meditation, there are no insignificant sensations, as they can all be potential entry points in connecting with the underlying resonance of the Divine Subtlety.
Every posture, every nuance of movement can be connected with the underlying “hum” of creation. This vibration/hum is the distilled essence of all that is felt in the body…and what is deeply felt has a way of focusing the mind!
This hum/vibration includes not only the familiar sensations of the inhaling and exhaling breath, the heartbeat, the weight of the body, etc., but it also includes the not-so-familiar sensations of fine vibrations and reverberations that are accessible but normally not considered.
Mind is like a liquid that fills the container of the body. What you feel can then be infinitely distilled to a most subtle essence…and this essence is experienced as a sensation that puts mind and body into a most delicious swoon!
When the body/mind/psyche enter into meditative trance/swoon, the feeling of the inner squeezing, contortion of the body, is like a churning of “cream” (of life force) in the spine until the “butter” of essence is created. The experience is felt as a ravishing pulsation of sweetness that radiates through the energetic field of the body.
The body/mind, when it “touches” the underlying “hum,” will begin to vibrate in resonance with the powerful current. The mind will be as riveted, focused upon the growing inner sensation that seems to naturally “push” energy upwards in the spine to the crown area.
Understand that the above experience can be described in a number of ways. For example: a giant snake spiraling up and around the spine, squeezing the energy to the crown area. Or…like taffy being pulled to infinite thinness up the spine.
There are numerous traditions describing the movement of the Divine Essence, Life Force, Kundalini in the body and spine. The important point to note is that these traditions (along with their meditative techniques) can be helpful when you actually connect with these infinitely subtle currents.
However, I don’t believe that techniques can impart the experience in a linear, step-by-step progression. They can be helpful in the beginning to establish intention, prayer and discipline, but at a certain point, the rigid practice of technique can get in the way. The Life Force, Kundalini, is such a wild, primal, oftentimes chaotic, disassembling force/energy! The pathway to it is not a neat and tidy, linear and logical, step-by-step process!
With this in mind, once you do have the connection, you will recognize how to use technique to deepen your attunement with this primal Life Force.
I do believe that meditation technique can be useful to prepare the body/mind/psyche for when Kundalini begins to tear your life apart, when it disassembles it, for purposes of putting it back together in a better way.