Safety and preventing arrest are two critical reasons to screen clients, particularly when you advertise on Backpage. Spending a little time on StripperWeb shows that girls get arrested and I know of some personally, some just body rub girls who have been arrested. It's usually just a fine and no jail time, but still, who wants that on their record? There are lots of different ways to screen and I'm not suggesting that my way is the best or even sufficient, it's just what I happen to do and since I've been asked to share, here it goes:
If a client is new, I ask them to provide some paperwork indicating what their day job is along with photo id. For working guys, it's usually a business credit card, biz card (with photo id of course) or work badge, pay stub, etc. If they have a full-time day job, they are probably not working as a police officer on the side. Of course in terms of safety, this "screening" provides little assurance. If I were working as an escort in a hotel, I'd bump it up to asking for references, and if they are a newbie, then there'd have to be some other requirements.
Because I work out of a studio, I never book appointments when there isn't at least one other person in the building. Like, I'm not going to do a 9 p.m. body rub, but 9 a.m., sure there's always someone there. Again, not perfect, but I feel safe enough with my system and I've never been arrested.
If you do ever get arrested, apparently you can hire a lawyer to have the charges removed. I forget the technical word, at a fee of course, but it might be worth it if you want to move into a different career.
Other things a girl shouldn't do is negotiate over the phone, e-mail or even with the client standing there fully dressed. Negotiations (do this for that) are a good way to implicate yourself. Don't leave a studio/parlor/strip club/hotel in the dark if you can help it (make sure he has left first). All this should be common sense but sex workers get comfortable and forget the basics.