Hi,
to be responsible gambler, you have to respect money and put aside a certain amount for gambling purposes. As davidpom mentioned in the first point, you can't spend more than you have or than you can afford to lose. There are numerous ways to restrain yourself from excessive, compulsive gambling. One of them is sticking to the bankroll management rules. Read about it in this article, I hope it will be helpful: 8 Golden Rules of Bankroll Management