Draping, plainly
You get on the table under a sheet and a blanket while the practitioner is out of the room. From then on, only the part being worked is uncovered, and it is covered again before anything moves on. Your back is uncovered for back work. One leg at a time, tucked. Nothing below the hip line is ever uncovered, at all, in any treatment.
This is not a courtesy that varies by practitioner or by mood. It is the standard, it is what Arizona licensing requires, and it is not something you should ever have to ask about.
The things people worry about
Body hair. Nobody notices and nobody cares. Practitioners work on forty bodies a week.
Not having showered since the gym. There is a shower here and you are welcome to use it, and if you do not, it genuinely does not register.
Falling asleep. Extremely common and mildly flattering. If you snore, nobody will mention it.
Where to put your clothes. A locker with a real key, in the changing room, not in the suite. Take the key in with you if you would rather; there is a dish for it by the table.
What to leave at home
Heavy jewellery and the good watch, not because anything goes missing but because taking them off and putting them back on is four minutes you would rather spend in the courtyard. And any expectation that you need to have done something to prepare. You do not. Read your first visit and that is the whole preparation.