However, as punters it is also easy for us to fall into the trap of expecting all "services" to be the same just because we are paying for them. But these ladies are individuals with their own preferences and prejudices, feelings and foibles, from the same gamut of backgrounds and relationships as we of the punter population, and deserve to be shown the same respect as anyone else.
Because the service she is selling is such a personal service, unlike any other service or goods for sale, it is imperative that the buyer and the seller should come to an understand at the very beginning of what the ground-rules, preferences and boundaries are. (However, what I am not particularly happy with are the artificial boundaries some ladies put up simply to extract extra cash).
If a lady is not comfortable with something you are asking for, then don't make the booking. If she is offering services beyond your comfort zone, then draw your line - if its in the middle of service just say "I'm not comfortable with that, lets not go there". Respect each others choices.
I have encountered a wide range or ladies' preferences, from the "star fish" that wanted no personal interaction at all and saw her role purely as a "receptical" for her client (never booked her again), to the almost sex-crazed nymphomaniac (a regular I see as often as I can cope with her).
Kissing restriction on certain erogenous zones (ear lobes, neck, nipples, toes, etc)? Respect her preferences.
Oral on you, yes, no, with or without? (Note in some Australian states, this is now a legal issue though how it can be policed beats me). Respect her preferences.
Blow-job - COF, Spanish, CIM, swallow? Respect her tastes.
Oral on her, yes or no? Respect her preferences.
Fingering - clitoral stimulation only or internal G-spot? Respect her preferences.
Use of toys? On her? On you? Food as toys? Respect each others preferences.
Fantasies and dress-up? Type? 'French Maid' might be OK, but 'baby diaper' might be too far. Respect her preferences.
'Dirty' talk? Respect her preferences.
Sexual intercourse itself is a given for 'escort' and brothel services, but recognize that ladies that opt for stripper and exotic dancing services are NOT offering full sex. So don't embarrass yourself and ask or pressure a lady. Respect her choice.
Then there are services beyond the 'normal' which are more likely to attract an extra charge and are more usually special offerings advertised.
Sex is meant to be an enjoyable activity, so don't spoil it for yourself or your lady by pushing beyond a person's comfort zone.