I didn’t really think much about bartenders till I became friends with a former bartender.  I didn’t know her when slinging drinks was her occupation, but she and I have been to many bars together and I learned a lot about the profession by absorbing her observations as I absorbed wine with her.

A bartender is often a blend of mixologist and psychologist.  Bar flies will tell their bartender deeply personal things they wouldn’t even tell their spouse or best friend.  A good bartender is also a sales person, suggesting food or maybe premium versions of the patron’s initial order. 
My favorite local hangout provides the perfect model for the right way to be a bartender.  Each staffer introduces themselves to new customers, they pay attention, engage in conversation, make suggestions.  They know their products.  These bartenders make newcomers feel as at home as regulars.  As newcomers become regulars, the staff remembers their preferences.  Another local establishment I frequent presents an entirely different experience.  The food is good and the bar is well-stocked.  The bartenders are friendly … when you can get their attention.  Customers have to flag them down like hailing a taxi to get a second glass of wine. 
I’m a pretty good tipper when the service is good.  Twenty percent is my minimum in those cases.  When the service is average, as in the case of my second example, my tip is exactly 15% to the penny, sometimes a fraction less.  Funny that the name of my second example includes the word ‘average’. 

A bartender’s job isn’t easy, but I consider their role to be an integral part of the bar experience.  If all I want is a drink, I’ll stay home and make it myself.  I go to a bar for socialization at least as much as intoxication.
Maybe I should say something to some of these barely-adequate barkeeps.  Maybe they just don’t know.  Or maybe the expectations of customers is low.  Mine are high.  Cheers.