Circular breathing is a technique I have been working with in my waking state (vaiśvānara in Sanskrit). I have been doing it as a prelude to my own practice, and I have taught it to my students. It is a practice that is remarkable simple, has no or few watch outs, and results in an increased presence to now.
To begin, find a comfortable posture. This can be lying down on the floor or seated on a cushion or chair. This should be a posture you can sustain for the duration of the exercise. Don’t do this when you are sleepy, or when you have just eaten (when “your body is a pantry,” as Swami Rama would say). Have a blanket nearby, and maybe a small pillow under your head, if you are lying down.
Become aware of your breath, how it flows in and out of your body.
Eliminate the pauses between in-breath and out-breath, and between the exhalation and the inhalation, so that your breath is smoothly, continuously, flowing.
You may find it helpful to begin breathing in at the end of the exhalation, and breathing out at the end of the inhalation. Or let your breath be like the ocean surf, flowing forward and backwards in each wave.
Now begin to visualize your breath as a ribbon that is continuous, and has one twist in it, so that it is a Mobius, a three dimensional object with only one side.
See the breath ribbon as an object that is within your body. Follow the breath as it flows along this ribbon. You may want to see the breath on the ribbon as a light that follows the ribbon, permeates the ribbon, IS the ribbon.
Maintain this concentration for a few minutes, then gradually let the breath find it’s own rhythm in you. When you are ready, open your eyes and return to your day fully relaxed and deeply refreshed.
I have suggested that this practice should not be done when you are sleepy. The human tendency is to fall into sleep when we become so deeply relaxed, and the intention of this exercise is to remain exquisitely alert. This simple practice will provide incredible rest, and you will return to your day revitalized.