I've spent some time in bars, so I think I can handle this one.
1) Observe the bar, some have an area or two "designated" for walkup, others expect you to shoulder your way inbetween people. There is usually an area bounded by two big silver or brass handles. This is so the bartender can get out in a hurry to help the bouncer, and in many bars it's where the waitresses go to get their orders filled. Do Not Go There, you are getting in the way of working folk, and are making other working folk wait longer for THEIR drinks.
2) If it's busy know what you want before you go up there. Save your experimentation and questioning for a slow period. When it doubt "Whiskey, Neat", or "Vodka, neat". If you're having a day "Whiskey, double".
3) If you'd like to run a tab proffer your credit card and ask. Some places don't do it, some don't take credit. Also have some cash Just In Case.
4) If you have a preference (for example I don't drink canadian whiskey straight, and I won't drink a whiskey and coke if they use pepsi. So I ask "do you have pepsi or coke" [1]) ask BEFORE ordering. If you really don't care you will (generally) be asked for a preference. The stuff in "the well" is cheaper, and if you're getting a mixed drink usually only matters for the first, second and third. After that either your bartender is a cheap bastard or you've lost the sublties. If you're drinking it straight, then it matters. Until the 7th or 8th anyway.
5) If you're paying cash HAND THE MONEY TO THE BAR TENDER, the bar is often damp with spilled drinks, assorted other fluids, bits of food (sometimes) and cigeratte ashes. HAND THE MONEY TO THE BAR TENDER. If you want him to keep the change, just walk away, he knows. If you're sitting at the bar and you want him to keep the change just sort of push it back towards his side. He knows.
6) Be friendly, say please and thank you. Bartenders have to deal with lots of shitty customers, don't be one.
[1] Pepsi? In a BAR? What kinda sick fucking joke is THAT?
It's subtleties like this that make me wish for the "how it works" signs I suggested.
OTOH, there could be some invisible filtering going on: perhaps bars wouldn't even want the kind of customer that doesn't have a "sponsor" that can accustom them to the many rules there.
On the third hand, establishments do resort to "how it works" signs when either a) everyone is more ignorant than they would like (e.g. sub shop Quizno's posting of how to order a sandwich), or b) the downside of not knowing how it works is severe (e.g. emergen...
I am beginning to suspect that it is surprisingly common for intelligent, competent adults to somehow make it through the world for a few decades while missing some ordinary skill, like mailing a physical letter, folding a fitted sheet, depositing a check, or reading a bus schedule. Since these tasks are often presented atomically - or, worse, embedded implicitly into other instructions - and it is often possible to get around the need for them, this ignorance is not self-correcting. One can Google "how to deposit a check" and similar phrases, but the sorts of instructions that crop up are often misleading, rely on entangled and potentially similarly-deficient knowledge to be understandable, or are not so much instructions as they are tips and tricks and warnings for people who already know the basic procedure. Asking other people is more effective because they can respond to requests for clarification (and physically pointing at stuff is useful too), but embarrassing, since lacking these skills as an adult is stigmatized. (They are rarely even considered skills by people who have had them for a while.)
This seems like a bad situation. And - if I am correct and gaps like these are common - then it is something of a collective action problem to handle gap-filling without undue social drama. Supposedly, we're good at collective action problems, us rationalists, right? So I propose a thread for the purpose here, with the stipulation that all replies to gap announcements are to be constructive attempts at conveying the relevant procedural knowledge. No asking "how did you manage to be X years old without knowing that?" - if the gap-haver wishes to volunteer the information, that is fine, but asking is to be considered poor form.
(And yes, I have one. It's this: how in the world do people go about the supposedly atomic action of investing in the stock market? Here I am, sitting at my computer, and suppose I want a share of Apple - there isn't a button that says "Buy Our Stock" on their website. There goes my one idea. Where do I go and what do I do there?)