If you give a money tip you are only doing something any other client can do. You need to be different to make an impression. Just a few words can be more effective; if you say "you're gorgeous " that's a commonplace, they hear it all the time. But , if you say "you are different to the other girls," they will say "how?" and you say offhandedly "Oh, I dunno, you're just classier." That approach is more likely to work because it touches every WG's weak spot - her vanity, and it puts her ahead of her competition. BS is a basic punting skill, it shouldn't be neglected.

If you feel you must tip cash, only do it rarely and generously, Christmas, Chinese New Year, don't let it become an expectation. Tho' I once got caught out with a regular who had 3 Birthdays in the same year.