I have maybe a slightly different approach to payment.... I always use an envelope to hold the dosh. Upon arrival, once I've decided that I'm staying, and that the services I'm interested in are available with no surprise extras, I usually put the envelope down on a table or windowsill and say 'That's for you'. What the WG does next tells me a lot about the sort of girl she is and how the punt is likely to go. If she snatches it up, fishes out the notes and counts them right in front of me, it is likelier to be a colder sort of service provision, and entirely about the money instead of what I will necessarily enjoy. If she just says thanks and takes it to stash it next door, it tells me that she is a careful WG, learning the trade, and perhaps lacking in confidence. Or that a Sergei or Mama-san is nearby who makes the rules about cash handling. However, if she leaves the envelope where it is and gives me a kiss and gets down to business, I figure she is a smart WG who has already decided that I am a genuine punter, and that I am far more likely to have a much better time with her.
Sure, it may be a 'hoor' as some say, but I see no reason to risk humiliating or belittling a WG by tossing cash at them to pick up. Better to treat them with some dignity if you want a better experience. Most WGs seem to respond positively to being treated decently, I've found. Some will still treat you like they hate you and can't wait for you to fuck off, but you just don't return to those. More often than not, the WG will treat you well in return, because they are often the ones who want to cultivate repeat custom with punters who show them a modicum of respect and enjoy their time with them. There's a balance to be struck between being a fluffy mug who gets taken advantage of, and being a bastard who WGs can't wait to get rid of!
