In Indo-Tibetan Buddhism, one of the foremost authoritative texts on the Bodhisattva path is the Bodhicaryavatara by Shantideva. In the eighth section entitled Meditative Concentration, Shantideva describes meditation on Karunā as thus:
Strive at first to meditate upon the sameness of yourself and others. In joy and sorrow all are equal; Thus be guardian of all, as of yourself. The hand and other limbs are many and distinct, But all are one--the body to kept and guarded. Likewise, different beings, in their joys and sorrows, are, like me, all one in wanting happiness. This pain of mine does not afflict or cause discomfort to another's body, and yet this pain is hard for me to bear because I cling and take it for my own. And other beings' pain I do not feel, and yet, because I take them for myself, their suffering is mine and therefore hard to bear. And therefore I'll dispel the pain of others, for it is simply pain, just like my own. And others I will aid and benefit, for they are living beings, like my body. Since I and other beings both, in wanting happiness, are equal and alike, what difference is there to distinguish us, that I should strive to have my bliss alone?"
- First repeat this several times for YOURSELF.
- Now focus it and send it to someone dear to you (May you be...)
- Send this to someone neutral. A neighbor, acquaintance, coworker, etc. (May you be...)
- Focus on someone negative or difficult. Someone that maybe you just don't like. Now send it to them (May you be...)
- Finally, send it to All Beings Everywhere (May all beings everywhere be...)