It is important to me that everyone I work with would recommend me highly to others, without reservation. You should always feel safe, comfortable, and know you're dealing with a professional.
Escorts are optional, but welcome at all of my shoots. I encourage any model working with a photographer for the first time to bring an escort to their photo shoot.
When working with any photographer for the first time, I'd suggest making a point of always having your cell phone handy, and to check in with someone you know at least once during a shoot to let them know you're safe. Also make sure that someone knows where you will be and that they should expect to hear from you at a certain time. They should also have the number of the photographer you are working with.
It's also a good idea to ask others the photographer has shot with about their experience during their shoot. In other words, check references!