"Then at last Avalokiteshvara arrived at the summit of Marpori, the 'Red Hill', in Lhasa. Gazing out, he perceived that the lake on Otang, the 'Plain of Milk', resembled the Hell of Ceaseless Torment. Myriad beings were undergoing the agonies of boiling, burning, hunger, thirst, yet they never perished, sending forth hideous cries of anguish all the while. When Avalokiteshvara saw this, tears sprang to his eyes. A teardrop from his right eye fell to the plain and became the reverend Bhrikuti, who declared: 'Child of your lineage! As you are striving for the sake of sentient beings in the Land of Snows, intercede in their suffering, and I shall be your companion in this endeavour!' Bhrikuti was then reabsorbed into Avalokiteshvara's right eye, and was reborn in a later life as the Nepalese princess Tritsun. A teardrop from his left eye fell upon the plain and became the reverend Tara. She also declared, 'Child of your lineage! As you are striving for the sake of sentient beings in the Land of Snows, intercede in their suffering, and I shall be your companion in this endeavor!' Tārā was then reabsorbed into Avalokiteshvara's left eye."
With this story in mind, it is interesting to juxtapose this with a quotation from the 14th Dalai Lama about Tārā, spoken at a conference on Compassionate Action in Newport Beach, CA in 1989:
Within Tibetan Buddhism, she has 21 major forms in all, each tied to a certain color and energy. And each offers some feminine attribute, of ultimate benefit to the spiritual aspirant who asks for her assistance.
In this case during the creation phase of Tārā as a yidam, she is seen as having as much reality as any other phenomena apprehended through the mind. By reciting her mantra and visualizing her form in front, or on the head of the adept, one is opening to her energies of compassion and wisdom. After a period of time the practitioner shares in some of these qualities, becomes imbued with her being and all it represents. At the same time all of this is seen as coming out of Emptiness and having a translucent quality like a rainbow. Then many times there is a visualization of oneself as Tārā. One simultaneously becomes inseparable from all her good qualities while at the same time realizing the emptiness of the visualization of oneself as the yidam and also the emptiness of one's ordinary self.
The end results of doing such Tārā practices are many. For one thing it reduces the forces of delusion in the forms of negative karma, sickness, afflictions of kleshas, and other obstacles and obscurations.
The practice then weans one away from a coarse understanding of Reality, allowing one to get in touch with inner qualities similar to those of a bodhisattva, and prepares one's inner self to embrace finer spiritual energies, which can lead to more subtle and profound realizations of the Emptiness of phenomena and self.
There are several preparations to be done before practising the Sadhana. To perform a correct execution the practitioner must be prepared and take on the proper disposition. The preparations may be grouped as "internal" and "external". Both are necessary to achieve the required concentration.