I have got 2 pops from the girls here in NJ spread across 3 AMPs which are widely reviewed in this site. The key unlike NYC AMP is to be upfront. Post house fees please make it clear either by saying something like "I want 2" and simultaneously holding 2 fingers. Sorry - this may sound like dummy's guide but its not. Their English is not good and thus need to clear in communication. At this point, all said okay or nodded or showed the thumbs up sign.
I usually provide the tip in advance and she usually leaves after getting it. I always tip the standard. Once she returns I ENSURE TO SPECIFICALLY AGAIN THE SAME QUESTION BUT THIS TIME ASK "I need to give you extra?" 1 out of 5 said yes and I gave the nominal increase she requested ; 2: shrugged and smiled. [I still gave them .. at the end, as i counted for the extra]; rest: told me the extra immediately when asked.
In contrast - standard escorts: in an hour its assumed and commonly advertised as MSOG. In NYC, THEY ask - "Two?"