When I went independent I had no clue about all this. I knew backpage and screen w your gut *rolls eyes* I felt lucky that I had a client make me aware of TER and other sites. The rest I got to figure out on my own. It turned out there were some things I had been lead pretty astray on, things that could have resulted in low ratings. They may have effected my ratings but I guess I did a good enough job to make up for it because I got pretty good ratings and reviews, even in the beginning.
I have only once discussed what was in a review w a client and that was only when he asked for another appt after he left me my worst review ever, unhappy with some things that were largley created by the location he picked. When I asked him to write another review after seeing me at my incall he offered to do it with me. I told him no, I don't want to influence you, just write what you honestly think. It's still not my most glowing review but we were both happy. I have also not asked a client to write a review (except for a couple that asked me to ask them when I wanted them to write one. In which case I waited till I haven't had one for a bit, they are good marketing and can be timed) I feel like asking opens the door to influence.
There is so much fear of deception in this industry. Unfortunately it's with good reason. When you hear stories of even top rated girls in bigger city's offering clients incentives, weather it was hinted at or direct how can you not question things?
Everyone can use help with marketing, no matter the industry. As far as the rest though just do your best and be respectful and responshble when it comes to communicating and showing up. That alone will get you good reviews. It's nice to be able to say my reviews are 150% honest and unmanipulated.
Marketing, make a website, not only does it help guys get to know you but it gives an aire of professionalism. I'd go look at websites and ads by the ladies that were doing exceptionally well for ideas for my ads and site. Be honest with who and what you are and do your best to convey it. Your not going to appeal to everyone but when people know what they are getting chances are everyone is going to be much happier.
Sorry for the long response but there is too much deception and it makes it harder for everyone. I'm not sure if you ment it but your question kind of came across as asking how to ensure good reviews no matter what.