"This is a meditation in which you have to be continuously alert, conscious, aware, whatsoever you do. The first step, breathing; the second step, catharsis; the third step, the mantra, ‘Hoo’.
"Remain a witness. Don’t get lost. It is easy to get lost. While you are breathing you can forget; you can become one with the breathing so much that you can forget the witness. But then you miss the point. Breathe as fast, as deep as possible, bring your total energy to it, but still remain a witness. Observe what is happening as if you are just a spectator, as if the whole thing is happening to somebody else, as if the whole thing is happening in the body and the consciousness is just centered and looking. This witnessing has to be carried in all the three steps. And when everything stops, and in the fourth step you have become completely inactive, frozen, then this alertness will come to its peak." Osho


More on Dynamic Meditation:

Osho,
Please explain what type of meditation techniques are suitable separately for the tamas, rajas, and sattva person. Why do you always give dynamic techniques?

"The dynamic technique is really a very rare phenomenon. It does not belong to any type; it can help all. To the person of tamas – lethargy, inertia – it will bring him out of his tamas. It will create so much energy in him that the tamas will be broken; if not all, then a part of it. If a man of tamas is ready to do it, it can work wonders because a man of tamas is really not lacking energy. Energy is there but not in an active position, not in an active state. Energy is there fast asleep. The Dynamic Meditation can work as an alarm: it can change inertia into activity; it can make the energy move; it can bring the man of tamas out of tamas.

"The second type of man, the rajas type, who is very active – in fact much too active, so active that he cannot find fields where to release his energy, he is in many ways a pent-up energy – the dynamic technique will help him to release, to be unburdened. After doing dynamic techniques he will feel weightless. And in life his hectic, continuous obsession for activity will slow down. A part of his obsessive occupation will dissolve.

"And for a person of sattva the Dynamic Meditation helps tremendously. He is not in inertia; there is no need to bring his energy up. He is not obsessively active; there is no need of any catharsis for him. He is balanced, purer than the other two, happier than the other two, lighter than the other two. Then how will Dynamic Meditation help him? It will become a celebration for him. It will become just a singing, a dancing, a participation with the whole. He will be benefited the most. "

Osho, Yoga: A New Direction, Chapter 2, Question 2