The main aspect of successful sports betting is knowledge. Knowledge is certainly power, and the more you've got, the more bets you will win. The main element to winning bets is feeling confident with your betting decision. The only way to feel confident is to conduct a little shopping around, learn about the teams, players and coaches, make your decision.
After you have done some investigation, you will have concrete reasons why you are betting in this way. This is much smarter than betting along with your gut instinct. Your gut feeling might win you a bet here and there, but in the future, you will surely find yourself losing more bets than you win.
The best way to determine if you have done enough studies to explain your reasoning in making that particular bet. If the argument you are making for one team over these guys weak and never backed up by much evidence, this is not a bet you ought to place. Alternatively, if your argument is powerful and persuasive, you need to feel very confident in placing that bet. The greater bets you set when you are confident, the harder bets you may win.