They like everyone else, provides me with a solid reference or two.  

When asked to visit a residence, I feel a little more relaxed once I check with a previous provider.  This is because as much a security in the hotel can be pestering, if something happens at least it gives us some percentage of help.  Most people do not feel comfortable with providers whom have drivers, but this also can ease nerves, because at least someone is there when the session is over; would be around the area if any problem arose.  Personally, I notify someone of my general location and what time I will be calling notifying that my session is over and I am safe.
When visiting a hotel, depending on the time of day/night atire may differ.  One visiting during the day would probably try to blend in with the crowd and wear something more casual, as opposed to at night maybe something more professional or business like.  Also, Monday's vs. Fridays atire will also differ.  
Personally, I feel more comfortable going to a residence, and building a friendship with that person in their own terf.  Guys tend to be more relaxed and have more fantacies they want to fullfill.