I wouldn't get too attached, but I would never treat one badly either. It is a buisness for her but in any buisness there is mutual respect. The woman knows what you want and when she provides it the best she can, you owe it to her not just in payment but in decent treatment. There are sorry providers that rush you and just want it over with and ones that do their best and at least act like they are enjoying it. There are also sorry clients; don't be one of those. That being said I have never given gifts, nor will I as these women that we all should respect are here today, gone tomorrow. Don't be afraid to chat with them or let them know your appreciate their care. I've been doing this (albeit infrequently) for about 14 years and I'm glad I did, but I make no illusions about their true feelings.
Don't get hurt thinking they love you. They don't, they just fuck you for a living. Keep that in mind and also that they don't hate you (mostly) or even dislike you. Maintain a friendly distance.