The main reason we play poker is to have fun. Some Texas holdem players argue that money is the actual motivation. I disagree because most people don't actually make money playing poker. Most people lose money. There are also other ways to make money, so why did we choose a risky game like poker to earn it? The answer is because poker is an enjoyable game.Most of the time.
Every once in a while someone does something ignorant in a game that makes you want to pull your hair out. For instance, one of my pet peeves is when players don't put their highest-denomination chips in the front of their pile. Even worse though is when the guy to my right whispers, "You know what I had that last hand and actually folded?" Surprisingly, I still don't care after all the times it's been said. I used to think that was useful insight into a players preflop hand selection, but now I just cringe whenever a flop has a pair of twos and that guy shoots me that quick look of anticipation to let me know that he wants to tell me something after the hand is over. You had a two, huh? And folded it? Wow.
1. Do not reveal your cards while a hand is going on. While it's not against the rules (some places may give a penalty), it is at least a horrible breach of etiquette. If you were not folding, you're hand will be ruled dead. The problem is that it can give one player an advantage over another and potentially ruin a pot for someone. Even if it is an accident, you should be apologizing your ass off.
2. If you folded and your cards would have made a great hand on the flop, don't reel back in your chair or bang your hand off of the table or let your stupid jaw hang open, letting everyone know that you would have hit that flop. In fact, don't react to the cards on the board at all. Again, it can potentially ruin a pot by giving some players an advantage.
3. Don't be mean by criticizing an opponent's play, being verbally abusive to another player, or by being cocky about how good you are (or think you are). On the flip side, if someone has met those qualifications by talking directly to you, the best thing to do is just smile and agree. "Yes, I got lucky there", "I can see how I might've played that wrong", and "Oh ya, I've heard of you before, I was told to look out" are all acceptable comments that will hopefully end the discussion. Don't let the sarcasm show though.
4. Don't blame the dealer. Also, don't wing your cards at the dealer or not tip him as a result of previous bad beat. They really, actually, and truly have no control over what cards are dealt. They are just there to do their job and they deserve respect.
5. Do not talk about a hand when you aren't in it. Giving advice to a live player is actually against the rules in most places. Simply talking about the hand is also in very bad taste though. The players who are still in the hand don't want to have to listen to your noise pollution when they're trying to focus on the other live opponents. So shut your mouth.
There are situations where a player who isn't in the hand can talk about the hand and it's universally okay.
One is in no limit when players go all-in and they are having problems counting chips and so is the dealer. Often players are flustered, having just made the biggest bet they could make and something goes wrong in the counting section of the brain. A player who doesn't have all their money at stake can often count much faster, so it is acceptable to speak up and declare their all-in.
Another instance is when a player does something like toss in an oversized chip and say "raise" but that nobody hears it and a few players call the previous bet before the bettor realizes that something went wrong. Before people start yelling, the dealer gets pissed, and the floor is called over, YOU should be the one to say that the bettor declared a raise. People are already angry at the bettor for not saying it loud enough, so they don't want to believe he actually said it. You as an unbiased third party seem a much more valid candidate to determine if the word "raise" was said than the person who said it.
Before you start betting like a madman when you get two eights in the pocket, you need to carefully consider all factors involved in solid preflop strategy.
The factors to consider are the number of players, how aggressive/passive the players at the table are, your bankroll, your position, and how much risk you are willing to entail.
Number of players: With 10 people in the game, it's much more likely that someone else has a strong hand in the pocket than in a short-handed game. Also, you'll need to be more cautious in larger games, as the chances of someone's preflop hand fitting the flop will be much better. More competition means stiffer competition.
How aggressive the players are: Assuming you've been playing with a few people for several hands, and you noticed some jackass is raising every hand preflop, you'll want to play tighter. Let the guy win the blinds (big deal) and nail him to the wall when you have a solid hand in the pocket preflop.
Your bankroll: If you have $2 left, you'll want to play extremely carefully and select one hand to bet on, hoping to get as many players involved as possible for a larger pot. You'll want to be all-in before the flop is dealt. On the flip-side, if you have $1000 at a $1/$2 table, you can take the high-risk, high-payout bets.
Your position: People in late position have the ability to influence the size of the pot much more than those in early position. This is especially true preflop.
Your tolerance for risk: Depending on your playing style, you may want to play more or less aggressively preflop. Players who shoot for larger pots, but don't mind a greater chance for losing a few hands will want to raise preflop, especially if they are in late position. Some players prefer to be as selective as possible preflop, grinding out a winning hand here or there. It really depends on your own style of play, and how you perceive the players around you.
You might also want to consider what cards you have in your hand. Naturally, AA is the best to start with. It helps if your hand is suited or if the cards are sequential in rank like a Seven and an Eight ("connected"). It's important to understand how your two cards hold up against other combinations of cards though.