Dharana
Patanjali says in Chapter 3, Sutra 1:
Deshabandhashchittasya Dhaaranaa.
The meaning of the above Sutra (or thread) is:
Dhaaranaa means binding the Chitta (mind-stuff) to one place. CHITTA is a Sanskrit word which can be explained to some extent by English words like being, psyche, or personality. The method below describes how you can BIND your PSYCHE to the SOHAM mantra. Try it!
Dharana is a prelude to Dhyana or meditation. Dharana means concentration. After withdrawing the senses from the sense-objects (Pratyahara), Dharana should be practiced.
A METHOD for awakening your PRANA via SOHAM mantra: Manas or mind, svasa or breath, and mantra or formula can be united to awaken the Atindriya Marga or para-sensory route / psychic passage between the Manipura, through the Anahata, to the Visuddhi Chakra.
Sitting in LOTUS POSE with the spine erect, when you breathe in, feel
that your prana (the VITAL FORCE, which can be felt as a current of
energy) is going up from your Navel Center (Manipura) through your Heart
Center (Anahata) to your Throat Center (Visuddhi); so when you are
breathing in, energy ascends and you say SO. Hold for a while (this is called KUMBHAKA, which is the goal of PRANAYAMA), and then breathe out.
While breathing out, feel that your PRANA (feel it as a current of
energy) is going down from Visuddhi back to Manipura; so when you are
breathing out, energy descends and you say HAM. The mantra SOHAM = SAH + AHAM. SAH means HE and AHAM means I. So, SOHAM means I am He. This "I" is your Higher Self, and not your Lower Self which dwells in lust and money. What is that HE? That HE is BRAHMAN! If you can stay with the up-down flow of PRANA and its unity with the SOHAM mantra with its meaning, you will start perceiving the rhythm of this creation and why you exist vis-a-vis this world... you will move beyond the psychic passage to the field of mysticism, where the YOGI dwells... This unbroken concentration on SOHAM will lead to DHYANA or meditation...