One of the things I like about Reiki is that the person receiving Reiki is involved in the session. There isn’t something for them to physically “do”, but their state of mind during the session and their willingness to try to relax as much as possible and be open is an important element. Reiki Practitioners do not control the energy in any way. We simply act as a clear pathway for the Reiki energy to flow. Your energy field knows how best to use this energy.
Here’s an analogy for how a Reiki Practitioner supports the person receiving Reiki. The person receiving Reiki is like a painter. This painter is truly gifted, but they only have eight colours available to them. In this scenario, a Reiki Practitioner is like a friendly paint supplier. They arrive at the studio and deliver hundreds of colours. They even open all the containers and set them up nicely within easy reach of the easel.
Now our painter has access to more colours and they can use them to create beautiful paintings with more subtlety. It’s up to them which colours make it in to their painting.
The paint supplier may have brought them more options, but the painter is still the one actually creating the art.