Rewriting the Rules of Workplace Communication: Bartender Sign Language

In an office environment communication is done through e-mails, phone calls, and face to face interaction. In a bar the noise level makes that type of interaction impossible, so most communication is through body language, yelling short commands or requests out, and a general understanding of everyones needs.
As a bartender in a club environment it becomes increasingly frustrating trying to understand customers who speak in low voices. Most communication with customers consists of them pointing to the bottle of beer they are drinking, and basic manners are thrown out the window because its a pain to yell PLEASE at the top of your lungs when there is only a 50% chance of being heard in the first place. Customers not drinking beer will generally say things like VODKA CRANBERRY and i acknowledge them with a head nod or by picking up my shaker tin rather than trying to say something in response. The thank you i get is in tip form instead of verbal, at least when i'm lucky.
It is futile to try to carry on conversations with customers after happy hour when the music is turned up, and when customers attempt this it does nothing more than annoy the bartender who wants to get you your drink and move on. So save the small talk, yell your drink order at me and be done with it!