Isn't establishing a good rapport with the wg the best way to get the most out of her?
The most for some is still utterly shit. Good escorts don't need much or frankly any chat. Those that do will ask questions to get something out of you anyway.
As VW says, make sure you're clean, on time, you've got the correct money, be polite, smile and just let her do the rest. You don't need to do anything else. If you really want, you can talk about whatever you fancy but don't let any chat take over the punt and make sure she doesn't turn what should be paid sex into just paid chat!