I haven't been to Jomtien in 5 years,. but then, you walk down the street, lots of boys at the bars (there is often seating in the street) they will say hi and try to invite you in for a drink. If you see a boy or a bar with mostly your type go in and take a seat, any boy will be happy to sit with you if you buy him a drink (he gets a cut). Ask a server (they didn't have a "mamason" when I was there), he will tell you details about the boys and round one up for you. you can "talk". If you like him, take him back. if not a small tip and try another.
When I was there, there was no off fee for beer bar boys. I thought they were all "free lance" work for tips and a cut of the drinks. Maybe that has changed?
Check out some of the Pictures/ You Tube videos to see what it is like.
Can any of the members point him at a how to?