A lot comes down to letting the bigger head make the decisions...
Best to stick to reviewed guys here or on Daddy's at first.
They won't want to be explicit on the phone, so phrase it more as the kind of stuff you enjoy doing. The price is for *their time*, not sex acts.
A little bit of caution and being willing to walk away if there are any red flags are important. Keep that in mind, find a guy you think you'll click with from his reviews, be safe and *have fun*!