Some say that everything is energy. from light. i'd agree with those and add there are many energies outside of certain ranges not easily seen/felt/experienced by all (yet). For me this is a beautiful gift from God/Spirit/All. we're granted time via lives and must experience everything. There is no death of our true energy / our essence. That's how much we're loved; God/Spirit wants us to experience everything, learn everything, do everything, all in love... & wants us to ever seek to be closer to that source via learning, experiencing, gratitude, improvement of self, and desire for only that continual closeness.
Combine faith, love, selflessness with mentalism and we can begin to feel different energies and can heal others and not ironically, we heal ourselves while doing so. This is the mind-to-mind thing shared between others without words but via energy & is communication nonetheless. Your physical body speaks to you, and given we're all connected, our highest selves can intuitively know where to place/hover our hands in order to heal the person on the table.
In the tradition I've learned, I always center & clear myself first. Sometimes I'll smudge myself w/sage or palo santo as well. Crystals / gemstones are often also used in grids and on different chakra centers. Power symbols (for those that know a bit of Reiki) are preformed at times over certain areas where it is felt needed/helpful. Sometimes the symbols are made mentally only or with the toungue on the roof of the mouth if the other hasn't yet been attuned.