In Part 2 of “Yogasadhanas In The Gita”, Swami Niranjan writes:
“Before one can focus on the awareness of the higher Self, the layers of mind have to be traversed. Just as to reach the bottom of the ocean one has to swim through many, many metres of ocean water, in the same way one has to go through many layers of mind to eventually realise and see the presence of higher consciousness within. The deepest part of the ocean is six kilometres deep and you have to swim all the way down. In the same manner you have to walk through six kilometres of your mind before you come to realise the presence of the supreme Self within you.”
He cites that in the Gita Krishna tells Arjun to begin with pratyahara, withdrawal of the senses. The turtle is used as an analogy–withdraw the mind and five senses as the turtle withdraws its limbs, tail, and head. The body becomes still and the breath is regulated. A good beginning, I think, can be the bumblebee/ buzzing bee breath/bhramari pranayama (see Calming The Storm which has the audio practice after the short story). Then equal inhalation and exhalation are recommended (see Samavritti Pranayama) in alternate nostril breathing/nadi shodhana.
“Sri Krishna gives Arjuna a sadhana, to fix the mind at the eyebrow centre and regulate the breath, make the inhalation and exhalation of breath as long as possible and in the gap between inhalation and exhalation, focus the awareness on the inner Self.”
The various simple pranayamas help control hyperactive thinking, passions, reactions, and emotions. This management of emotions leads us to the inner stillness within.
Other factors in the Gita are karma yoga–the attitude with which we work changes kama or work to karma yoga (path of selfless work).
To get the full benefit of the teaching, a reading of the whole article is suggested.