Having spent an unreasonable amount of time in food service, in several different states in the US, I generally think that I've seen most of what can be seen (though I do realize that claiming I've seen it all does a grave disservice to "it all".  But really, people.  I don't need to know).  Despite the quasi-iconic public concept of the surly bartender who hides in the corner and has to be coaxed out like they're a mouse and you've got a pocket full of cheese, most bartenders do want to offer their customers timely and friendly service in a welcoming atmosphere.  In a tips-based economy, it's the smartest way to make money.  And in my time in restaurants and bars, I've encountered a vast and often confusing array of ways customers deem acceptable to get a bartender's attention.  In the interest of public service and to help out my bar brethren across this great land, I give you the do's and don'ts of:

THE DON'TS

The Tapper

The Tapper thinks the most effective way to get his drink refilled is to tap his empty glass repeatedly on the bar as though he's tapping out distress signals in Morse code.  Unless you're warning me about icebergs dead ahead, this is an inappropriate way to communicate.  I can let you tap all day.  Plus, if you're that anxious that you need to bang your glass on the bar until you get another drink, then you don't need another drink, and I would recommend trying some yoga, or perhaps taking up meditation.

The Barker

The Barker thinks that raising his voice above the din of a bar is a surefire way to entice a bartender over.  The Barker doesn't seem to realize that he is the human equivalent of WRITING IN ALL CAPS and as quickly as I will delete the email written in that manner, so will I dismiss the person who behaves in this manner.  He may express himself in a way that seems callous (Hey, you!) or try to sound charming and/or endearing (Hey, honey, sugarplum, dollface!).  But no matter how you phrase it, he's still the obnoxious drunk yelling at you from across the bar.  Avoid whenever possible.

The Whistler

Very closely related to The Barker, The Whistler shares the sentiment that making loud noises to attract the bartender is effective.  The problem is, The Whistler chooses the same manner in which he calls his dog in for dinner.  The Whistler doesn't always necessarily whistle, per se, but he will clear his throat repeatedly or make "Pssst!" sounds.  One memorable time, the owner of the bar I worked in was on duty when a customer tried to attract his attention by making that repeated "psst psst psst" sound you make while trying to convince a cat to come near you.  The owner turned around and, without missing a beat said, "You'd better have some Friskies in your pocket if you're calling to me that way."  At least that once, the errant customer grew momentarily embarrassed enough to stammer out an apology before asking for a refill.

The Grabber

If I'm ever back behind the bar, do not--and I mean DO NOT--ever reach all the way across the bar and touch me.  I will wreck you.

And so we come to the end of my general guidelines for DON'T bar behavior.  This is by no means an exhaustive list, but it's a good place to start.  Do note that the "DON'T" behaviors are generally demeaning and/or hostile and/or aggressive.  Use that as your measuring stick for what not to do, and you should be off to a good start.

THE DO'S

The Cash Presenter

Most bartenders, you see, are fairly bright, and understand that being attentive to the people standing or sitting at the bar impacts their tips.  If someone stands at the bar with money in their hands, bartenders will generally investigate such an event because people don't randomly walk around holding money.  In a bar, it's a specific signal that means, "I want something and I'm ready to pay."  Yes, it's true.  Money talks.

The Discreet Signaler

You can gesture to your bartender, so long as you're chill about it.  If your bartender looks like he's in the middle of a conversation and isn't likely to end it any time soon, you can gesture.  If you want to get drinks ASAP for yourself and that fine individual you're successfully chatting up, you can gesture.  Or if you realize you need to leave, you can do the universal "I'm pretending to sign my name" gesture.  Gesturing does, for the most part, imply necessity so don't go overboard pointing and waving at will!  Then you become the barfly who cried wolf, and your gesturing just becomes a silent extension of The Tapper and nobody needs to cross into hybrid signals because then everyone is unhappy.

The Empty Glass Bearer

The Empty Glass Bearer is the mellowest of all patrons and has an inherent understanding that a bartender intends to do his job to the best of his abilities.  A bartender who's even half-paying attention knows that an empty glass requires some sort of attention.  Empty Glass Bearers tend to be easy customers for bartenders to deal with--they're not overly demanding, they don't need babysitting, and their lack of aggressive behavior towards the bartender generally means the bartender will like them.  Bars are a great place to have a high-fivin', belly-bumpin' good time, but not necessarily with the bartender, who has five or fifteen or sixty other people to manage simultaneously.  Have faith that the bartender will get to you.  While people may think the squeaky wheel gets the grease, when you're in a bar it's the quiet glass bearer who gets the best consistent service.

It's true.

I'd love to hear about other bartender-approach behaviors that I might have forgotten or have blocked from my memory.  Feel free to comment!