1.) Be aggressive You can't be a good basketball player if you are tentative and uncertain of what you will do on the next play. Great players play with decisiveness. Great players are aggressive.
2.) Make a 2nd and 3rd effort on every play It's one thing to make a good effort. But great players keep trying until they succeed. If you aren't immediately successful on a play, keep working and trying until you make it happen.
3.) Think positive Believe you'll be successful, and it's more likely to come true. If you take the court doubting yourself, doubting your abilities, and scared that you'll fail, well guess what: you probably will. Think positively, act like you'll get the job done, and then go out and make it happen.
4.) Be confident in yourself Not only do you have to think positive (see #3 above), but you have to believe in yourself. Great players know they are good. They know they'll win most battles. They play with confidence and it shows in their performance level.
5.) Take good shots It may sound silly, but taking good shots is a big part of shooting a high percentage, and getting lots of playing time. If your range is 16-feet, don't take 23-foot off-balance jumpers. Sometimes players shoot the ball because they don't know when they'll get another chance to score. Make sure you're the type of player that takes good, high-percentage shots.
6.) Be a good teammate Don't ever forget that basketball is a team game. Your success (or failure) is based on how you play, and how your team plays. Help make the players around you better, and you'll be surprised at how good that will make you.
7.) Get up and down the floor quickly Whether it's running up the court on a fast break, or sprinting back on defense, good players run the floor well. Getting up and down the floor quickly puts pressue on your opponent and puts you in a position to make good things happen.
8.) Listen to your coach Your coach determines whether you get in the game or not, and how much playing time you get. Work hard in practice, and listen to your coach during games (about which offense to run and which defense to play). If a coach doesn't think you're listening, your playing time will suffer.
9.) Play great defense Coaches love players that play good, tough defense. Even if you're having a tough night on the offensive end, you can still contribute to the success of the team by playing great defense. There are lots of big-time college and NBA players who aren't all that great offensively, but who are big-time defensive players. Defense can get you lots of playing time.
10.) Stay out of foul trouble Playing good, smart basketball means staying out of foul trouble. You'll commit plenty of fouls by playing good, aggressive basketball, so avoid fouls for reaching with your hands on defense, or for over-the-back calls while going for rebounds. No matter how good a player you might be, you'll spend plenty of time on the bench if you get yourself into foul trouble.
11.) Practice hard Practice is how you prepare for games. Whether it's shooting around on your own, or scrimmaging at your team practice, you've got to work hard. If you get lazy, and decide to take it easy during practice, your game will suffer. Push yourself, work hard, and you'll improve as a player.
12.) Go up strong inside Anytime you play in the paint, you've got to be tough and play strong. There are lots of bodies, elbows, arms, and hands in the lane. If you make a post move, or rebound the ball on the offensive end of the floor, go back up strong. It's no place to be tentative, weak, or afraid.
13.) Become a great free throw shooter Everyone should work to become a great free throw shooter. You can improve your scoring average, get more playing time, and help your team win games, simply by becoming a clutch free throw shooter. A big part of free throw shooting is mental. So work on having a good free throw shooting routine, and being confident that you'll knock the shots down.
14.) Be the player you'd hate to play against As a player, I hated playing defense against guys that were aggressive, smart, constantly moving without the ball, who took high percentage shots, went up strong inside, and crashed the offensive boards. And I hated playing offense against aggressive, strong, smart, fundamentally sound players who played great D and never made anything easy for me. Be that type of player. Be the player you'd hate to play against.