When you're done eating at a restaurant, you place you knife and fork on the bottom right of your plate, with the fork left and the knife to the right, with the sharp side pointing towards the knife.
This is an example of etiquette in a restaurant. In the poker world there is also something like etiquette.
Many players, especially recreational players, don't know that there are certain no-go's in the world of poker. You can't really blame them for it and from these players you're just going to have to accept it, in exchange for the action you get from amateurs. From professionals you can expect that everybody treats each other with respect at the tables. This is more an exception than the rule. Often people just don't realize that certain actions at the table are very low and disrespectful. I will start off with the lowest form of bad poker etiquette.
Many people don't know what this word means, and it is often confused with slowplaying. Slowplaying is simply hiding the strength of your hand in order to get more money into the pot.
Slowrolling means that you are the last to act in a hand, and you wait with making the call while holding the absolute nuts. Someone goes all-in and you have on a board that shows . There is now way to get more money into the pot, but still you wait to make the call, although you know there is no way you could lose. This is extremely low. Because you're giving your opponent the idea that he has the winning hand. Why in Gods name would you do such a thing? You can't lose the hand anymore and you achieve nothing by taking your time. People think this is part of the psychological game of poker, but it is one of the worst things you can do. It doesn't serve any purpose and you will lose a lot of respect from the other players at your table.
Another form of slowrolling is to wait before showing your hand on a showdown. Imagine you call another player on the river with on a board showing and your opponent shows . You didn't trust the river card and therefore only called your opponent on the river, so he has to show his hand first. What I have seen many times is that the player nods, knocks on the table and takes a last look at his cards while shaking his head. At this moment you're giving your opponent the idea that he won the hand. Often they will then pretend to muck their hand, and just before they throw away their cards they turn them face-up with a grin on their face.
If you know you have the best hand than just show your cards immediately and don't enjoy the delay. This is a very obvious asshole-move that serves no purpose what so ever. The higher limits you play, the more important it is that you follow etiquette. From my own experience, especially from Vegas, I know that from this moment, I immediately lose all respect for that player and just throw my chips in his direction.
Celebrating the winning of a hand should be done with modesty. Put yourself into the shoes of your opponent and imagine what it's like for him to lose the hand. If you lose a hand and your opponent jumps up and screams "YEAH!" and starts cheering with his friends, you would be extremely irritated. Don't get me wrong, there's nothing wrong with being happy that you won a hand. Winning an important hand in a tournament and doubling up can certainly be celebrated. Simply say "yes" to yourself and clinch your fist.
If your Aces hold up in an important hand or a big pot it is normal to feel a certain sense of stress-release, but nobody wants to see a guy standing up on his chair screaming for joy. Nobody else in the rooms cares that you just won that hand.
Keeping your celebration modest is even more important if you end up winning with the worst hand. If you win against after going all-in preflop, don't get up screaming that you're the best. I myself wouldn't want to draw attention to the fact that I got my chips in with the worst hand and just got lucky.
So again, out of respect for your opponent, just stay calm. Saying sorry doesn't really help either, because you know as well as he does that you're not sorry for winning the hand. Often the best thing to do is to just give your opponent a polite nod, as in saying that you know you got lucky. Something you definitely shouldn't do is start talking to your opponent. "What was I supposed to do, I had kings." Excuses from somebody that just got lucky, that he had no other choice, are extremely irritating. This brings us to another form of bad manners.
Saying things at the end of a hand should also be avoided. Something that is very 'In' at the moment, but extremely rude, is players saying "ship it" after winning a hand. If you play online and say this to yourself then you're not really hurting anybody. But when playing in a casino, saying things like "ship it" or "send it" after winning a big pot is extremely rude. As if your opponent isn't trying his best to win the pot.
As mentioned before, coming up with excuses can also be very irritating. If you got lucky in a pot where you were the underdog, just keep your mouth shut and be happy that you won the hand. "What did you want me to do, I had an Ace?" or "So what, you got lucky the last time" are examples of "Just shut the **** up!" Just respect your opponent and be happy that you won the hand.
Another important form of etiquette is not to talk a bout a hand that you are not involved in. Don't give hints as to what you folded, or what you think other players are holding. Everyone has to play their hand for themselves, and the players in the pot are the only ones that should be talking about the pot. Don't say things like "Wow, did you flop a set or something" after a player raised. At the end of the day it's really none of your business, so just wait until after the showdown if you wish to comment on the hand. Even if you are in the hand but not in a heads-up situation it is rude to think out loud or ask questions to one of your opponents.
If you want to be respected at a poker table, you will have to show the other players respect in return. Slowrolling other players like they are dirt will definitely affect the way the other players at the table will treat you in future. If I get slowrolled by somebody I will make sure that on the next showdown I will turn over the nuts with a smile on my face while starring at him and provoking him. This person doesn't deserve to be respected and I will show him how irritating and low his behavior is.
So make sure that you play with respect for your opponents and put yourself in their shoes in some situations. If you lose a hand to a 2-outer, the last thing you want is a guy dancing on his chair laughing at you. So don't do it yourself.