Hi Dee Reiki initiations have the physiological effect of causing a big jump in our vibrational energy up towards the finer psychic energies, we become more spiritually attuned and more psychic, seen clairvoyantly a grey mist lifts from the aura and it's the single most effective thing we can do towards development.
The more reiki we practice on ourselves the more attuned to spirit we become it's a meditative or spiritual practice from one angle and has the immediate effect of expanding our aura raising our sensitivity which makes it ideal to use before psychic work.
I always visualize the reiki power symbol and call in the energy before reading consciously opening up psychic channels calling in guides and teachers, it's good practice to get into a ritual of using the power symbol because it's very protective.