Reiki asks for no special preparation — you can arrive exactly as you are. Still, a few small things can help you settle more easily into the hour.
Nothing is required
It is worth saying plainly: there are no rituals to perform and nothing you must do to "get ready." If you turn up straight from a busy day with no preparation at all, the session will be perfectly fine. Everything below is simply a way to make it a little easier to relax.
A few gentle steps
If you would like to prepare, these help:
You stay clothed, so loose, easy clothing makes lying still more pleasant.
A light stomach and less caffeine make it easier to settle and rest.
Try not to rush in from something stressful; a few unhurried minutes beforehand helps.
If you like, quietly note what you would welcome — rest, ease, calm — and then let it go.
On the day
Arrive a few minutes early so you are not hurried, turn your phone off or to silent, and let the practitioner know anything relevant — how you are feeling, or any areas you would rather they avoided. Then the best preparation of all is simply the willingness to lie back and let the hour be quiet.
If you remember only one thing: arrive a little early and let yourself slow down. That alone is preparation enough.