Just found this excellent short intro by Lama Gursam -- taken from his teaching on Medicine Buddha, but applicable to generation and completion stages in general.
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Milarepa was asked by a student, how do you practice
generation stage? Milarepa said,
"
When we meditate the body appears as Medicine Buddha, but at the same time it is the selfless nature of the rainbow body. So how to practice the speech? Speech becomes an echo, like the emptiness. And the mind itself is naturally empty, like the light of the sun and moon."
This explanation is very useful. We need to get the essence teaching and put it into practice. The idea is that in Tibetan tantra yoga,
generation is the pure visualization of all sentient beings as a deity, as Medicine Buddha himself. What makes sense for me when doing this practice is to
have no negative thoughts to others. Just stop. Bring more loving kindness and thoughts of compassion to others. So it is very useful to do this kind of practice...
After the generation stage comes the
completion stage. Whatever Medicine Buddha is holding or wearing dissolves into light into the form of the Medicine Buddha. And Medicine Buddha's form dissolves into the seed syllable HUNG
ཧཱུཾ་ (if you don't know the Tibetan character, you can visualize the English letters stacked). The seed syllable dissolves from bottom to top. Then the top dissolves into the state of emptiness. Then you should remain for a few minutes in this state of emptiness, according to your time and ability. Then reappear in the form of Medicine Buddha.
What is the purpose of the completion stage? The purpose is to master the process of death. Death is not easy. Anyone who works in a hospital knows this. The process of death is the same as the completion stage. We can feel the energy of everything we sense and do. When we become old, our physical body doesn't work any more, and we can no longer feel the energy we used to feel. So everything is dissolving. The body no longer works at the time of death. The energy of the elements no longer function. We experience the process of death and what happens at that time.
With the practice of the completion stage, we are more aware of what happens, and the fear of death goes away. The accomplished practitioner has total confidence and no fear of death. They have a strong energy of the mental states.
Normally the mind loses its energy at death. In an accomplished practitioner, the mind becomes much more stable than it was before at death.
That is a brief description of the generation and completion stage. The person who has accomplished the practice has a very strong energy and can benefit others fearlessly and without doubt.
http://www.lamagursam.org/med_buddha.html----
What I took away from this as a summary, then, was:
1. Generation stage increases our compassion, since by seing all beings as deities, we drop negative thoughts.
2. Completion stage increases our confidence, since by familiarizing ourselves with the process of death, we reduce fear.