It's perfectly fine to be a loud-mouthed, sloppy, unwashed slob who screams when he loses and yells for joy when he wins -- but only if you are playing blackjack on line in the privacy of your home. In a casino, however, it is a very different story.
There are a number of things you can do (or not do) to make yourself a more welcome player at the table. Most of these require simply common sense, others involve some knowledge of the game and its traditions.
For a start, blackjack tends to be a quiet game. You generally won't see the kinds of celebrations familiar to those who enjoy craps or slots. Keep in mind that others at your table are trying to concentrate on their own hands, or perhaps mentally keeping track of what cards have been dealt, and your talking will only serve to disrupt them.
There are times when a short word or two with the dealer is fine. Nobody will object when you say "Hit me" or ask for more chips. In most cases, however, even your conversation with the dealer can be silent. A hand signal will tell him if you want another card or not. Splitting cards will demonstrate exactly what you want without you having to tell him. When you want to double down, it is enough to simply place the correct amount of chips next to your original bet.
Should you light up that cigarette you want? Conversely, should you object if the person next to you is smoking? If the house rules allow smoking, go ahead if you want. If you don't like smoke, play elsewhere. Some casinos ban it completely. Others allow it only at specific tables or in certain rooms. Don't argue about the rules. Smoke only where it is permitted and accept it if your neighbor does.
Never bring food to your table. The casino may provide you with drinks but it is a rare one which allows you to eat. It takes up room and can slow down your playing.
Keep in mind that everyone else at your table is there to play, not to wait. When you see your cards, and the dealer's open card, you should immediately know how you will play that hand. True, seeing what other players get may change your mind in a few cases, but when your time to play comes be ready.
Never, ever, complain when someone else at the table takes a card which you think he should not have. When you announce that he took "my card" you are not only being rude and insulting but you are also showing your ignorance. If you are sitting with a 10, and the player before you has 18 and asks for a hit, he is not reducing your chances of winning. Before his card is shown you have no idea it is a perfect ace or that card you most feared -- a six. Indeed, he might well get that six and have you wind up with the ace.
Bad play by someone else may well cost you money -- but only if you are betting on his hand. There is nothing wrong in you doing so, but it gives you no right to tell him how to play it or to complain if he makes a mistake. If you don't like how he is betting, you are free to bet along with another player.
Don't offer advice to other players, no matter how much they might need it. If the man next to you is holding a 2 and a 3 and doubles down against the dealer's 10, refrain from telling him that it is a very foolish bet. For a start, it will delay play. More than that, most people who are at a casino to enjoy themselves are not interested in getting lessons. Of course, if you later find yourself drinking next to him at a casino bar, you can diplomatically suggest that he learn a little about the game before going back to the tables. Conversely, don't ask the person next to you what you should do. While an exception to this can be made if he is a friend, in general most people at your table will be there to play their own hands, not yours.
The one blackjack etiquette question which no two players will agree on is how much you should tip the dealer -- if anything at all. There are some who give a chip every time they win a hand. Of course, in the long run this guarantees that the odds will turn against you so strongly that you will lose. There are others who give a chip every 15 or 30 minutes. There are still others who will only give a chip when they leave the table -- and even then if they leave as winners.
Personally, if the dealer has been courteous and showed an interest in his job I give him a chip when he is replaced or if I leave the table -- whether I am ahead or behind. The size of that chip? That depends on table stakes. Just as you would give a larger tip in an expensive restaurant than you would at a local diner, your tipping at a $500 minimum blackjack table should be larger than one which accepts $5 bets.