I prefer underwear or swimwear over naked. Different styles on different days is a good idea. It doesn't even have to be a bar, watching boys in water or or playing ball games and picking one would be fine. For bars, non-smoking and no loud music for me.
Everyone has to be available. I avoid places that have a reputation of boys who do not go with customers, or boys outside to lure customers in, but never on stage (Toy Boys comes to mind). I dislike mixed gogo and beer bar (like Winner Boys, where boys might be outside or inside; I want everyone in view).
Bar can be in a quiet area with little advertising. I prefer current Sunnee Plaza over the bright lights and music and many people at Jomtien Complex.