These are my realizations in my years of sportsbetting:
Never do impulsive betting.
My priorities and considerations in making a bet:
1. Psychoanalysis of the match-up (situations, match-up history, news about the players or team, streaks)
2. Sports physiology, science, sports medicine (injuries, fatigue, etc.)
3. Number Trends and statistics (ATS, Over/Under history, etc.)
Bet to enjoy the game and NOT to make a lot of money out of it. I consider Sportsbetting as an investment, with no short-term cashout in sight. Do not lose hope when you lose. Just stick to your losing team and you will hit the jackpot after some time.
Consider that athletes are humans too. They are not robots that go by the statistics and trends all the time. They have emotions and personal issues as well. Games and situations have psychological implications on them. You have to empathize them to know what they feel about a certain game, hence you will be able to predict the team's performance.
It is OK to listen to your gut feel sometimes.
It is OK to bet on the team which you know and the public as well is almost certain to lose. You'll never know.