The thing is, the enjoyment is very much dependent on how you get on with the client. By this I mean, if he comes in with a smile on his face and he is clean or willing to go have a shower and generally in a good mood, then pretty much I'm going to enjoy the booking.
If he responds when I kiss him, then I'm likely to enjoy it.
If he cuddles me back, strokes me, plays with me and stimulates my body, then I'm going to enjoy it.
If he responds to my touch and says things or makes sounds that confirm that he is enjoying what I am doing, then I am going to enjoy it.
If he makes me orgasm, I'm going to enjoy it.
If he makes me gush, then I'm going to enjoy it etc, etc.
However if he sits on the bed and just lies their rigid and does not want me to kiss him and starts ordering me to do this and do that, then I am not going to enjoy it, but I will do it, as that is his preference and I am there to provide a service. However, I may wish not to see him again, because it is rare for me to gain enjoyment in this way.
Also... if he chats with me, talks to me with interest and as an equal, then I will enjoy being with him and likely enjoy his company more.
When you work with people, often the enjoyment is a two way thing and I would say most of the time, if you have enjoyed yourself, so has the service provider and I think those that don't get that sense of enjoyment out of the work, don't last that long, as you just couldn't keep forcing yourself to do something you don't enjoy at all.