Don't resort to vulgarities (no matter how socially accepted they have been) or gesticulation to get the attention of bartenders. Whistling, finger snapping and name-calling (using lame terms like "honey" or "buddy") give the impression that you're being patronising.
Instead of shouting at bar staff (saying the music's too loud isn't a great excuse), tapping your coins or credit cards on the counter, and waving madly (with money in your hand), simply say something along the lines of "Excuse me, when you have a chance, please..."
Don't attempt to jump an invisible queue just because you're convinced that no one else can see you doing. Attentive bartenders are usually aware of who comes first. Exercise patience, and be considerate to other equally thirsty patrons. Take action only if you think you've been held up longer than it should take.
Avoid unnecessary stress by going for seats that allow you to make eye contact with the bar staff easily. Sit directly opposite the till, or where the beer pumps are located. Be careful not to abuse your position as bartenders who have perfected gaze-avoidance techniques can ignore obnoxious drinkers all the same.
Want a refill? Slide your empty glass towards the bartender, and away from yourself. You could also place your money or hold the empty glass in your hand. Progressively, use body language and facial expressions to help you: perch your elbow on the counter and adopt an expectant, hopeful, or somewhat anxious look so that he can sense your needs. Smile and let him know that you appreciate his service when you eventually catch his attention.
If the bar is busy, don't ask for more drinks right after you have placed your order. And once you have been served, step away from the bar and let someone else order. Don't hog the counter like a stubborn stain.
