1. Treat your server like a person, because guess what, they are
Maybe say a quick "hey, how's it going", or respond to your server's greeting. Even just, you know, smile. No one wants to serve your resting bitch face, so put the same fake frozen smile on that you give your work colleagues, because it's good to be civil.
Also, if your food's terrible, it's probably not your server's fault, it's the kitchen staff's. Or the owner's for insisting on a shitty preparation style. Ask the server what can be done, and nicely, because if you talk instead of yell, they're probably going to be apologetic and try to figure out a way to get you a better meal. Kindness may even get the meal on the house.
2. Clarity will get your everywhere
Read the menu, ask questions if you're not clear about something. Even better, ask your server for their recommendation because the best judge of the dish is probably the person that sees it being prepared, witnesses customer reactions, and wants to please you because they want the tip. Be clear and have no fear.
3. Speak up when you're ordering
One of my pet peeves is when the bar is clearly packed and so loud that everyone's already yelling to have a conversation with each other, and customers roll their eyes at me when I can't hear them order. Your server has the same hearing capabilities as your friends, strangely enough, so make an effort to have them hear you. Worst to worst, just point at your menu, non-verbal hand gestures beat out passive aggressive facial expression any day.
4. Sometimes, you just gotta be patient
Take a look around the restaurant. Is every table around you taken? Is everyone waiting for their food/drinks? Now, take into account how many servers there are to look after the section. Your server is only human, and is only as good as the organization and management of the bar/restaurant you're at. If things are taking too long, ask them why, and you'll probably realize that it's a delay out of their control. Don't hate on your server for the restaurants problems only because they're the only person you can bitch at.
5. Don't subject your server to your shitty mood
Had a bad day? That sucks, but it most likely wasn't your server's fault. And guess what? Based on how you treat them, they can either heighten your annoyance, or try their hardest to make things better. Really, you're just another table to your waiter/waitress, and if you're going to give them shit without a valid reason, they reserve the right to hit back. With sass, and not punches, of course.
6. If you have a reservation, be on time
You can't expect a bar/restaurant to hold your reservation for an hour. The normal etiquette is to hold it for about 15 mins, before giving it up. Get your life together and be on time, or if you're really in a bind, maybe call ahead and let them know you're running late. Your lack of time management and constant-lateness is no ones problem but your own, and definitely not your friendly server. Apologizing would be a nice plus, but that might be hoping for too much.
7. Don't clutter your table space
Do you really need your cellphone, sunglasses, keys, handbag on your place setting? Probably not. Keep the clutter confined to your apartment, it's really just going to get in the way of your waiter/waitress serving you. Most restos have coat racks you can hang your stuff on to, and purses/bags can easily just go under your chair. I assume you like having condiments AND elbow room when you're eating. You'll also avoid the horror of spilling water on your smart phone, which is just asking for spill-age as it sits face up and unprotected on the table.
8. TIP, for fuck's sake. TIP
Really shouldn't have to tell anyone in fucking 2013 to tip, because yes, minimum wage for servers is still shit, and yes, most of them really REALLY rely on customer tips to make rent. The standard tip is 15-20%. Not 10%. If you're still tipping 10%, you're being cheap and outdated, because inflation. So, if you're strapped for cash, maybe take into account how much your meal plus tip is going to cost you ahead of ordering, so that you don't tip your server 10 cents or some shit like that. Foreign customers don't get a free pass either. If you can figure out how to get to Montreal, you can figure out how the tipping system works.
9) Don't tell your server to make your drinks stronger. Order a double instead.
Most bars now work with an Azbar system, or some equivalent of it. This means that your bartender really doesn't have a choice in the amount of alcohol they add to your drink, and asking them to make it stronger will get you nowhere. Don't be cheap, just order a double. This doesn't apply to places that freepour, but those are getting pretty rare, and even then, your server isn't going to hugely alter alcohol content because they're probably going to get into shit for it. More often than not, your server will give you a cute 'for sure' + wink face, then just give you the same amount, only to giggle as you smugly drink your cocktail, none the wiser.
10) Don't hoard your table.
Just feeling like getting one drink today? That's cool. But be aware of the fact that getting one drink does not give you free reign of the table for hours on end. Places will usually not care if its a quiet time, but if it's a lunch/dinner rush and conversation with your friends is going exceptionally well today, just order something else. If you all really don't want to order anything else, respect the restaurant and move your asses to a park or a starbucks or something.
Try out these points and see how they improve your bar/restaurant experience. Got anything to add to my list of customer grievances? Comment below!