In Western Reiki, most teachers of Usui Reiki have never even heard of Byosen, Hibiki, Hatsurei Ho, or many other Japanese Reiki techniques that are part and parcel of the original system of Reiki as created by Dr. Mikao Usui, and are still being taught and practiced by the memorial society he set up in Japan in 1922 before he crossed over - the Usui Reiki Ryoho Gakkai (Usui Reiki Healing Method Learning Society).
Typically in Western Reiki, a new student is taught a specific pattern of hand placements for either self-treating or treating others. This usually consists of 12 to 14 or so hand positions called "holds" that correspond to all the major systems of the body (nervous system, digestive system, respiratory system, etc.), the 7 (or 8) major chakras, and all the major organs of the body. They are also taught to additionally treat any areas of concern that the client or "receiver" is presenting like back pain, knee pain, foot pain, headaches, and so on.
It's important in the beginning of the training to just establish a system of where the hands go, but at some point the student should be taught how to feel or scan for Byosen. " When there is a life energy block or a disturbance in health, there are always minus waves (negative waves) in the causal area." (Hiroshi Doi in an interview with William Lee Rand from "An Evidence Based History of Reiki" by William Lee Rand). The technique to sense Byosen in the hands is called Byosen Reikan Ho. To be able to do this, the student has to develop a strong sense of "feeling'" with the hands, a sensitivity. I discussed this in my last post here. This comes easy to some but not to all, and there are things you can do to increase sensitivity in the hands like placing a drop of Lavender oil in the center of each palm.
Hibiki is the sensations or feelings in the hands that the practitioner picks up when they are able to sense the Byosen in the energy field by slowly moving their hands through the energy field of the client (scanning) for this purpose. Examples of this would be hot or cold areas, tingling n the fingers, an electric shock type of feeling, or just resistance, like they've hit an energetic wall.
In Japan, the ability to sense Byosen and be aware of Hibiki is a required skill. In Western Reiki, as I said, many teachers are not even aware of these techniques let alone are teaching them. Some teachers do tell their students to eventually treat their client using only their intuition as to where their hands should go and for how long they should stay.
One of the things you can do to develop more sensitivity in the hands is a Qigong and T'ai Chi exercise called "pulling taffy". Pulling taffy is performed by holding your hands up in front of your chest, palms facing towards each other about 3 or so inches apart. Then you focus your mind on the energy between the two palms, and begin to slowly pull them apart a few inches and then slowly push them towards each other, never touching, but maintaining at least 2" between each palm. Do this for about 3-5 minutes daily or until you really began to feel the sensation one feels when they take two magnets and try to push them together or pull them apart.
Another technique is to put your right thumb pad into the center of the left palm and turn it clockwise several times with very light pressure. This opens the palm chakra. Then switch - put the left thumb pad into the right palm and repeat the technique for about 3-5 turns in each palm.