I can't add much to what's been said before, only give a bunch of +1s. Unfortunately, I suspect that most of the women who could benefit, and profit, from this advice won't ever see it.
In general, I want to spend time with women who make me feel like they care, if not about me, then my business.
Specifically, that means:
--dressing like she wants me to notice her. That may mean hose and lingerie, it may mean business attire, it may mean jeans and a cotton shirt with a ponytail; it doesn't mean looking like you just got back from day-long excursion to Wal-Mart.
--smelling fresh. Women in strip clubs and in the professional world know the power of scent; not as many providers do.
--cleanliness. From your location to your restroom to your body, I shouldn't have to feel at any point like I need a king-sized bottle of hand sanitizer. If you sleep where you work, or if you see multiple clients daily, at least throw a clean sheet over the covers before I get there. If your facilities don't allow me to wash up, have a box of baby wipes handy. If you kiss, have mouthwash handy; I'll use it, and you should, too.
--some of aren't very good at expressing desires or taking the lead; try to find out what we might enjoy and accommodate us or lead us if you can.
--surprise me with something different. I suspect that most of us are doing this because it's the only way we can get laid, at least with the frequency we desire, and so are just happy to have our basic needs met. Give us an adventure.
--afterwards. I usually send thank-you e-mails or PMs; I rarely receive any. But do you realize what it means to a guy to have a woman say she really would like to see him again? Even if it's just business, it's good business, especially if it's done with a personal touch. Bonus points if I occasionally get a hi-how-ya-doin e-mail or PM.
You really want to go the extra mile? I knew a woman once who endeared herself to a client she hadn't seen yet by picking him up at the airport during a layover and going to a restaurant with him before taking him back to the airport. There wasn't any BCD on that trip, but there were several afterwards. Some office-bound guys get tired of the same old lunch routine; even if BCD isn't possible, an hour hear and there when you have nothing else to do might pay off -- though you do have to watch for guys who will abuse the privilege. The woman I just mentioned got a lot of repeat business from me by picking me up at the office and letting me buy her lunch at The Crescent several times.
An extra mile-and-half? Surprise your client and bring a female friend. (Yes, it's happened no, not with me.) Trust me, he probably won't mind.
Just MHO, and worth what you paid fr oit.