Ok, im one to admit a couple of years in a cocktail bar in Cardiff (cap city of Wales) dont make me a stunning barperson by anymeans. My working flair (in the traditional sense of the term) is ok and have had working experiance in one of the busiest cities in the uk, I know theres a time and a place for it. I would also like to think that my product/recipie knowledge is good as well, but i know that its only a tiny scratch on whats out there.
The thing is for the first few months working in a bar I hated it when people came in, looked at the menu and then asked for a cocktail that wasnt on it, when asked what was in it, looked shocked and didnt know themselves. Im not joking but a lot of the time they also commented on the lack of professionalism and badly stocked back bar (if they knew the ingredients but we didnt stock the schnapps/spirit) to my face which made me feel pressured and embarressed.
Now I feel much more able to cope with the situation having extended my working knowledge, but i still feel p**sed off when newer bartenders get into that situation and I can see the customer really enjoying them squirm. Now its one thing for joe bloggs off the street to feel good about poking through holes in someones knowledge but for other bartenders to do it to bartenders I just dont get that at all. Its happened to me a few times before and its really frustrating when I see other newer barpeople around me get hassled by people in our trade giving comments like, 'you really dont know what your doing' or my personal favourite 'you call yourself a cocktail bar' which is funny because just because we dont know a cocktail that isnt featured in our menu and we dont stock cachaca we are suddenly not a cocktailbar anymore.

I personally don't understand all the who-ha over cachaca anyway, it is disgusting straight, and white rum is better tasting in any cocktail using it.

Customers will always be b#st#rds. Even now after 6 years of bartending I am still amazed at how some customers look at the menu for ten minutes THEN ask if you can make a caipirinha, mojito, etc etc. Why not just ask in the first place?

Customers never seem to know what goes into their favourite drinks. Or even what it looks like. Or what it tastes like. Or where they drank it. So just jump in with a recommendation, or alternative. "How about a Mojito/ Caipirinha?, or a Seabreeze?"

Some customers enjoy complaining, even when you try your best, and they see you struggle as well. Thanks is all you will probably get, but no tip.

American customers are the ones to watch out for, just smile and ride it through. They will be gone eventually.

One American lady came up to the bar after I had sent her Grand Marnier on ice out, in a whisky (rocks) glass. She told me it was a Cognac, and that she drank it all the time, and it should come in a snifter glass. Didn't we know anything? I responded that it wasn't a cognac, which she then denied. Fearing a yes-it-is/ no-it-isn't type of exchange coming on, I produced the bottle for her, and pointed at the words "Liqueur", which were on the bottle.
You also get this with Southern Comfort (which also has liqueur written on it).

I feel for you about the annoying customer, even if she got something different than what she was execting she shouldn't condescend to you. But for the record, she's not that far off the mark. Grand Marnier is a liqueur but it is based off of Cognac (i.e. brandy), albeit Cognac that undergoes several additional steps to produce the final product. In the States the default way to prepare the drink would be neat in a snifter. I've had people ask for GM on the rocks (which I serve in a rocks glass) but they have to request it as such. I'd say the same about most other sweet liqueurs as well (e.g. Amaretto, Frangelico)

its always a request thing is'nt it?
think liqueurs should be served in a liqueur glass, which is without ice, if you wanted to get technical,
but find the best thing to do in that situation is ask how they'd like it served to as to avoid confusion, you know, that old customer often right thing.......

Awkward customers... They do crop up, and I have to agree with the last comment, they are always right (even when they're not)!
I prefer the "Kill Them With Kindness" approach advocated by my good friend Mark Drew. As long as you're consistently polite and cheery (and not condescending or smarmy) any rude or difficult customers will find your attitude hard to fault and will have the 2 choices; Either leave or stay and cheer up themselves and stop being so bloody awkward.

(PS, I also hate the call for 27 Mojitos for Tracy's birthday group right in the middle of a hardcore dispense shift, but it goes with the territory I s'pose).