1. Sit erect with no stiffness in any part of the body. It would be ideal to sit on a flat surface, instead of sitting on a cushioned surface. If no options are available, cushioned surface can also be used.
2. Push the abdomen out during inhalation and contract the abdomen during exhalation. This is important. Breathing should be slow but deep.
3. Close the eyes very lightly and focus the eyeballs on the tip of the nose, near opening of the nostrils.
4. Push the head slightly backwards. Upper arms should not touch the trunk and there should be sufficient space in the armpits, say about two or three inches. Marginally raise the shoulders, say about one to two inches.
5. Now everything is set. Watch the breath in the forehead area. Visualize pushing the breath during exhalation towards ajna chakra. This can be done by contracting the abdomen. Vibrations and tingling sensations will be felt. Be with that sensation for some time or as long as possible. In the beginning stages, about five minutes would be very ideal.
6. If sensation is not felt, slightly move the head a little forward and backward during exhalation. At a particular point, vibrations can be felt. If still not felt, move the shoulders slightly up or down, may be by an inch or so.
7. Once the vibrations become intent, raise the eyeballs to focus ājñā chakra and feel the sensation entering deep into the ājñā chakra and feel the bliss. Try to feel the sensation at back of the head. This is a straight line drawn from ājñā chakra towards the back of the head. This is known as back head chakra.
8. Towards the end, concentrate on navel chakra for a minute and then open the eyes.
This can be done at anytime and the only precondition is that the stomach should not be full.