You will need to exfoliate the day before your tan, paying particular attention to elbows, knees, ankles and dry skin areas. Some exfoliates contain oil and if you use them on the day of your tan it can create a barrier to the application.
Before your tan you will need to shower to remove any moisturiser, deodorant or perfume. Having any of these on your skin will affect how the tan looks. Wax/shave at least 24 hours prior to treatment, to allow pores to close preventing dotting.
You can choose to wear as little or as much as you feel comfortable in during your tan. Most customers wear a dark pair of knickers or bikini bottoms. If you do not want tanning lines you can always stand naked.
It is best to wear loose dark clothing when you attend your tanning session or bring some clothes with you to put on afterwards.