I came across this topic on ThaiVisa Forum; How much a tip for one drink at a bar?
As usual a lot of troll replies but mostly from guys going to girly bars.

So, just what do you think is a fair/decent tip at a beer bar or go-go bar or a single drink or, even multiple drinks?

For me it is always 20 Baht unless I have multiple drinks and am enjoying the service of a cute or good waiter in which case he may get another 20 Baht in his hand.

I do notice that many farang customers stick with only one tip no matter the cost of a drink/meal. 20 Baht.

For reference sake I did a Google Translate of "tip" from English to Thai and the result was 20 บาท !!!