Within yoga, mantras are based upon sounds that reflect the energy of our divine nature. The word mantra comes from the combination of two syllables: "man," meaning "to reflect," and "tra," meaning "agent of." Let your mind absorb in the sound of the hum—in your internal chanting and your actual breath.
Find a comfortable posture for meditation. Place your palms facing up in Jnana Mudra (forefinger and thumb touching). Bring your attention to the breath. Begin to employ the simple mantra So hum ("I am that"). On the inhale, say So, and on the exhale, say hum. Keep your focus on the sensation of your breath while silently repeating the sacred syllables So hum.
Let your mind come to stillness. There is no place to go, nothing to do, So hum, So hum. If a thought (vritt) arises, come back to the mantra So hum. Practice it for 10 to 20 minutes. When you're finished, bring your hands together in Anjali Mudra (prayer position) to soak up the peaceful energy that you cultivated through your meditation.