The main aspect of successful sports betting is knowledge. Knowledge is certainly power, and the more you've got, the more bets you'll win. The key to winning bets is feeling more comfortable with your betting decision. The only method to feel confident is to conduct some on-line research, learn about the teams, players and coaches, and then suggest your decision.
Once you've done some investigation, you will have concrete reasons as to why you are betting in this way. This is much smarter than betting with your gut instinct. Your gut feeling might win a bet here and there, but in the long term, you will surely end up losing more bets than won by you.
The best way to determine you have done enough scientific studies are to explain your reasoning in making that particular bet. If the argument you are making for one team over another is weak and never backed up by much evidence, this is simply not a bet you should place. However, if your argument is powerful and persuasive, you ought to feel very confident in placing that bet. The greater bets you add when you are confident, the more bets you'll win.