Recently (Jan2022 Nice Boys Pattaya), the one boy I was interested in was engrossed in his phone, so I had to ask mamasan to call him over. Not a good start, but it all worked out well and I would take him again.
I find it important to establish whether they're Vietnamese. I'm often disappointed with Vietnamese (it could be just me) and this factors into my final decision.
It's not just you, it applies to me as well. Whereas boys from Cambodia, Myanmar and Lao get bonus points (from previous positive interactions with their compatriots).
I discuss neither activities nor tip with the boy. But then I'm easy to please; if you want sucking (the boy you) or fucking (you the boy) you have to make clear in advance that he will perform these activities. Everyone has to find their own style (negotiating activities and tip with the boy or not).
I pay the exact amount on the bill. That way, no wait for change (I have read about bars/waiters who leave the customer waiting, in the hope he gets impatient and leaves without collecting his change) and no chance for short-changing.
I keep my notes in order in my wallet, with a business card as separator between small (20-50-100) and big (500-1000) notes, no chance to grab the wrong note.
Before taking a seat in a bar and ordering a drink, I stand a few seconds in the door to assess the situation in the bar. If the number of boys is below 10, I can assess if there are boys worth a closer look, and if there are none, I make an excuse and leave. If I can see smokers or smell cigarette smoke, or the music is too loud and there I can't spot any boy who would compensate for these inconveniences, I tell door staff and leave.