To grow in spirituality, we cannot allow the mind and/or the lips to be external from us. Hesychasm means "to keep stillness."
Control the inward and outward movement of the breath, even holding it back a little. This is to control the mind and the body at the same time.
Fix your eyes on your chest or navel
Pay attention to yourself: never leave any part of your soul or body without surveillance.
"In this way, you will become unapproachable to the spirits that attack you from below" (St. Gregory Palamas, the Triads, C. I. ii. 9).
"If we judge ourselves, we will not be judged" (1 Cor 11:41).
Paul was "ravished to the third heaven, and did not know whether he was in the body or out of the body" (2 Cor 12:2) for he had forgotten all that concerns the body. (St. Gregory Palamas, the Triads, C. II. ii. 8).
Control sensations
Work on liberating yourself from the passions (even elated emotions)
Detach from external things
Remain undistracted
Over time this will become secondary and eventually involuntary.
"Such men, in effect, practice a spiritual Sabbath, and, as far as is possible, cease from all personal activity. They strip the cognitive powers of the soul of every changing, mobile and diversified operation, of all sense perceptions and, in general, of all corporal activity that is under our control; as to act which are not entirely under our control, like breathing, these they restrain as far as possible" (St. Gregory Palamas, the Triads, C. I. ii. 7).
"You will then have the blessed experience of David and you will address yourself to God, saying, "the shadows are no longer darkness thanks to you, and the night will be for me as clear as the day, for it is you who have taken possession of my reins" (Psalm 138:12-13).
The idea is to achieve a kind of quiet in body and soul.