Personally I know many great gamblers, and they all have the same thing in common... Money managements skills. Normally being a gambler tends to come with being poor at managing your money. Most gamblers will end up losing a lot more than they think simply because they are not managing their money properly. So learn this first, keep track of every penny going in and out, and make sure you're never losing more than you can afford.
Experienced gamblers do not gamble every time, because they also know that regular gambling will not in their favor. When they realize that now it is time to quit, they dont wait in casino and leave the place. A good gambler always gamble only those games in which he has great experience and he can use gambling tactics and strategies as well to win the game.
Also, a good gambler will know his limit and will never break his own rule. Once he reaches the targets, win or lose, he will immediately leave the game. Good gambler has plan while the bad one will follow their emotions.