Chenrezig Practice
Invoking the bodhisattva of compassion through visualization and mantra.
Chenrezig (Avalokiteshvara) practice cultivates compassion through visualizing the bodhisattva and reciting Om Mani Padme Hum. This is the most popular practice in Tibetan Buddhism.
Om Mani Padme Hum.
This mantra is said to contain all the Buddha's teachings.
Karandavyuha Sutra