pratyahāra — sitting in a comfortable posture with the spine erect one begins to withdraw one’s attention from external stimuli while paying attention the breath. Every time the mind wander you bring it back to the breath. One can also use a mantra like so-ham or even om-shanti to regulate the breath. The breath is connected to the mind so to quieten the mind one needs to regulate the breath.
dhāraṇa — means a focusing of the now quiet mind by using a mantra or any other device to center the thoughts upon. In Tantra the recommended technique is to use the images of the gods and goddesses or an image of one’s tutelary deity (iṣṭha-devatā) visualized within the heart or above the head. Christians can use a pleasant image of peaceful Jesus — remember what you meditate upon you become, so the purpose is to achieve an identification with the deity.