Remember: Manners cost nothing and are worth millions.
1. Do read the cocktail menu before ordering, and when you have the bartender's attention, know what you want (and what your friend wants, too).
2. Also, know what kind of establishment you're frequenting. If you're at reservation-only, super-cool speakeasy known for making the best craft cocktails in town, don't order a Long Island Iced Tea or a round of Jägerbombs (and definitely don't get mad if they won't serve them to you).
3. Don't ask "What is good today?" or "Make me something good." Says Duff, "you'll get chicken."
4. Don't order rude or "nasty sounding" drinks, it's demeaning to both parties. (As Duff so eloquently put it: "You kiss your mother with that mouth?") Basically, don't order a drink with a name that includes a body part that is normally covered with clothing.
5. Always tip well on the first round, and never tip with coins (unless perhaps you're in Europe).
6. Don't expect a free drink or ask what the bar's "buyback" policy is — especially before you've even ordered your first drink.
7. Don't order each individual round of drinks with a credit card — please run a tab.
8. Don't snap your fingers or whistle at the bartender to get their attention. "Lassie is not going to make your drinks."
9. Don't confuse service with servant.
10. No PDA in the bar, keep hands and tongues to yourself. Remember, this is their office — just because the lights are low and you're drinking doesn't make it OK.
11. Don't — or at least try to avoid — ordering a "slow drink" when you're at a busy bar. Asking for a drink like the Ramos Gin Fizz (the original recipe requires that the drink be shaken for 12 minutes) in a crowded bar isn't going to win you any friends.
12. Don't expect the bartender to know everything about every drink that has ever existed. And no "geeking out" unless you know the recipe (and as Duff points out, "there's really no excuse with iPhones these days).
13. Don't name drop.
14. Bartenders, if you're out at another bar, don't expect special service just because you're "in the biz." And if you're visiting a friend who works behind the bar, don't expect them to have a ton of time to socialize with you. "You may be off duty, but they're not."
Last but not least