Hardly any, at some times none at all (but I don't mind, I prefer it). Especially for escorts I have never met before, my punts are normally arranged in advanced via email / AW messaging system (rarely ever on the spur of the moment). I'm also a bit phone shy, so I try and avoid calling escorts if I can. I also feel that important details that I want are normally left out of a phone conversation, something I can express much better, and in detail, in any email or message rather than a phone call.
At around the time of my meet, it is normally a text message conversation confirming my arrival and / or apartment details. Good enough for me.