What is the best place for outcall?

1. A big crowded hotel
2. A small empty hotel

big

Hard to be anonymous when you are the only guest.

dressing the part and carrying a brief case or computer bag.  Don't act suspicious and treat the housekeepers right with ample tips to keep your room supplied with clean sheets & towels.  Grease the palms.

Big and crowded is best. Traffic to you will not be noticed. Keep the room neat and either bring extra towels or tip the cleaning staff to get the sizes that you need.