An attunement is a word used by people not using the Usui System of Reiki. The word we use under the Usui System is initiation. It is basically a process the Reiki master does to the Reiki student to open up the channels in that person's body so the Reiki is able to flow through that person's body and out of their hands to flow into someone else. It is the main reason you must take a Reiki class, in order to give Reiki to other people. Even though you know all of the hand positions and symbols and history-all there is to know about Reiki, if you haven't gone through your initiations the channels in your body have not been opened up and you will not be able to capture that energy and pass it on to other people. As far as what happens during actual initiation, there is nothing scary. The Reiki Master will place their hands in certain places on the Reiki student's body and say something with their hands in a certain place and that opens up your body's channels. That is really all there is to an initiation. You do have to take off all of your jewelry if you are wearing metal; you have to take off your shoes because your feet have to be grounded to the floor. You can sit or stand but your feet must be touching the floor. You don't normally feel anything during initiation but it is something that you do and then you are ready to perform Reiki.