adultwork is most widely used in this forum.
Two ways for your punting:
1. Search on adultwork on your own, grab some fab pics, check their rating and feedback first, if lots of nice feedback, then do a recheck on UKP to see if there's any report of them (copy and paste the girl's register name or number ID to UKP)
1) if there's many positive ratings, then should worth a visit,
2) if there's many neutral or negative fb, then you should AVOID the girl,
3) if there's no report of the girl, then you should be caution and check the register date, if she's new, then you can either give a try or not, if her register date is old but with 0 fb, then you should also AVOID her.
2. Simply read through the whole review threads on UKP, grab some interesting review and check the girl pic to see if you fancy her or not, if yes then you can book her.
PS. Sometimes if you really fancy a girl and found a positive report on UKP, please also search if there's any other report of the same girl, probably there's loads negative reports hidden in the archive.
If you have any other question, feel free to ask