Reiki is delightful.
You can expect to be and stay 100% fully clothed. You may experience meditation music, tuning forks, crystals, essential oils, aromatherapy and other alternative healing methods or tools during your session. But ultimately with Reiki, you are fully clothed and the session is done with you either sitting or lying down. The practitioner will draw symbols over your head and in her hands, set an intention for healing and protection, then (usually without touch, or using very little touching) the practitioner will use their hands to give you Reiki.
Reiki is very calming, relaxing and stress reducing. It is great for getting us out of our own way and letting the body heal itself naturally.
Reference: https://www.quora.com/What-should-I-expect-at-my-first-reiki-session-1