Shortly after I took my Reiki training I offered to practice Reiki without charge, once, on a few of the members of the Baha'i community. A few accepted. One notable one refused - she didn't want to accept anything free and didn't have any money at that time to budget for it.
This was a dear friend, however, who had multiple health problems. I didn't want her suffering if there was something I could do about it. Her main problem about which she complained was digestive problems with frequent trips to the bathroom. So, since I knew she was receptive to trying Reiki, just didn't want something for nothing, I figured I could gently give her a treatment at a Baha'i Feast.
She was sitting at a table visiting with other Baha'i friends so I quietly came up behind her and said, "Don't mind me, I won't do much of anything but stand here." I put my hands on her shoulders and asked the Reiki energy to help her where she most needed it. Had she not been receptive I would have moved, but she didn't mind having my hands on her shoulders.
A few weeks later she called saying now she wanted to make an appointment. Her digestive problems and frequent trips to the bathroom were gone, and the only thing she could attribute it to was the Reiki. She'd been to the doctor and been using multiple medicines, none of which had made any difference. It wasn't until after she had been treated with Reiki that things began to change.
My Reiki Master taught me that the exchange of energy is important and one should not treat others with Reiki unless they show that they value what you are offering in some way. It is a principle that my life in other areas has taught me is to be respected. In the case of my friend for whom I did a free treatment because I was still becoming accustomed to this healing modality, the exchange of energy was delayed, but it was there. Knowing I helped her with a very uncomfortable problem was a great way for the energy to be returned.