1.Tee: One player on the tee, at a time. Stand even with the ball well outside of the teeing ground, left or right, while each player hits. It is a breach of etiquette to stand behind a golfer on the tee, or anywhere else on the golf course. No golfer should have to ask you to move out of the way anywhere on the course, but especially on the tee, where players are concentrated like nowhere else. If you are a following foursome and arrive at a tee already occupied by the group in front, wait well off the tee for your turn. Joining them on the tee to watch the shots is a breach of etiquette, but if you do, follow the positioning rule above, at the very least. Always, remove your peg from the tee after hitting. It is a breach of etiquette to pound your tee into the ground or to leave it embedded in the teeing ground.
2.Speed of Play: Always play without delay at all times. Paramount in this category is to be at your ball, ready to hit, when it is your turn. After the tee shot, all the way to holing out, the order of play is always farthest from the hole first, and there really are no exceptions. Always carry two uniquely-marked balls. Limit your divotless practice swings to just a few seconds, and never practice swing towards anyone. On the green, study your shot alternatives, line of putt, and putting strategy while others are preparing to hit. You should always hit well within 45 seconds of the previous golfer's stroke. The only way to judge your speed is your position relative to the group in front of you. You are in position if, as you approach your next shot, they are just moving off. Don't lag behind or crowd unnecessarily the group in front. Never talk or tell stories that in anyway, even for a few seconds, delay play. There is plenty of time between shots while walking or riding to the next shot for discourse and jocularity. Consider the score card after hitting, while proceeding to the next shot, never on the tee or green.
3.Cart use: Golf carts should speed up play not slow it down. After the tee shot, proceed to the first ball and drop off the player, then proceed, safely, to the other ball. The dropped-off player should take extra clubs, if there is any doubt. As a general rule, don't wait while the other person disembarks, hits, reembarks and before proceeding to the next ball. Enter the cart with your club in hand and then exit to your bag before hitting the next shot. No need to go the bag twice for every shot.
4.Gimmies & Mulligans: Never give a shot that matters unless it is beyond the realm of remote possibility that the player could miss it. A one-foot putt takes about as long to putt as to pick it up. The essence of the game is putting the ball into the hole and it is a courtesy to allow that to happen whenever possible. Mulligans are never allowed. Strategy in match play sometimes requires a give-putt situation, but in reality these "gamesmanship" maneuvers should be kept to a minimum and play allowed to take its normal course where skill and proficiency prevail over tactical machinations.
5.Bunkers: When you leave a bunker you should remove all evidence that you were ever there. A few extra careful strokes with the rake to smooth the sand is always required. Think of the times you have had to hit from another's footprints or inconsiderate raking.
6.On the Green: Fix your ball marks like a craftsman, leaving no bare ground and an even, smooth surface where the ball mark was. Never dig under a ball mark and leverage the soil upwardly with your tee or tool: this dislodges and extirpates the tender plant structures. Pull the surrounding grass gently to the middle of the mark, starting at the highest point. Never stand along the line of another player's putt, front or back. Get completely out of the way. Again, standing even with the ball left or right, at a considerate distance, is always correct. Never talk or whisper while another player is putting. When you mark and replace your ball on the green never advanced it even infinitesimally, or appear to advance it. One of the most carefully-watched moves a golfer makes is marking and exactly replacing the ball. Be precise in this process, developing a system that is obvious and beyond any possible criticism. When removing the flag, don't drop it onto the green with a slap; either lower it gently or remove it to the first cut around the green. The player whose ball is closest to the pin has the pin responsibilities. Never lean on your putter while on the green, and when retrieving your ball keep your feet and weight well away from the hole. Return the pin carefully without any damage to the hole. Proceed to the next hole immediately upon holing out.
7.When Another Player is addressing the ball: There are only two things that every other player should be doing when a player is addressing the ball: standing absolutely still and watching the player hit. Movement is unacceptable. Talking is unacceptable. Fussing with equipment is unacceptable. Looking around is unacceptable. Stand still and watch the shot. If you can't render this simple courtesy, then you do not belong on a golf course.
8.Clearly state your score when holed out: Making other players ask what you had on the hole is a breach of etiquette. At the time of holing out, as you retrieve the ball, clearly state, "Par," or, "bogey," or, "Eight." Check the card occasionally to insure accuracy. Don't say, "I'll take a six." Golf is all about accurate scoring. After the game is over the appropriate handicap adjustments can and should be made. Incidental to this rule is the requirement for each golfer to have a standard USGA handicap. Without an official handicap, you are not able to truly compete in golf, and in every match you play you have brought an element of unfairness to the game. Accurate handicaps provide the only fair basis for competition. Playing without a handicap is a breach of etiquette, especially in light of how easy and inexpensive it is to officially obtain one.
9.Settling Up: Always have the exact amount needed to settle the game. Saying, "Do you have change for a twenty?" is a breach of etiquette.
10.Temperament: Babe Ruth said, "It is hard to beat a person who never gives up." This should be your guide to behavior and temperament on a golf course. Golf is a game of days, next shots, and handicaps. You are never out of it until you get mad, become beligerent, start throwing things, in other words, until you give up. Never blame other golfers for your bad play out loud or even quietly to yourself, if you want to play well. Never blame another player for enforcing and championing the rules of golf. Don't explain why your shot was bad, or good, and never yell out or whine after hitting a bad shot. Don't be so competitive that you forget that golf is a game played competitively for enjoyment. Play like a gentleman (TFG edit..."play like a lady."), in demeanor and attitude, because, in golf it is not what happens to you, it's your attitude towards it that determines the ultimate outcome. Which would you prefer: a career round in the midst of bad temper, bad humor and embarrassment over your lack of decorum, or, a 10-shots-over-your-handicap-round where you still thoroughly enjoyed the effort and the game? Scoring and playing well is what golf is about, but that's not what golf is all about.