Cy the Cynic says that life is like a tin of sardines, and everybody is looking for the key.
Nobody has a golden key to success at bridge. The game is simply too demanding. Your scores will depend on two factors. One is how well you and your partner play. That means reducing the number of avoidable errors you make. The other is how well your opponents play; the ability to give opponents a problem is the mark of an expert.
In a team match, both Souths landed at six spades, and West led the ten of hearts. Both declarers won with the ace and cashed the A-K of trumps. East threw a heart.
At one table, South saw that four diamond tricks would give him a discard for his losing club. He took the K-A of diamonds and next the queen, but East discarded.
South still had a slim chance. He cashed the king of hearts, ruffed dummy's last diamond, took the A-K of clubs, and exited with a trump. If West had held one more heart and one fewer club, he would have been end-played. But West actually cashed the queen of clubs for down one.
At the second table, South's approach was different. After he took the top trumps, he gave West a problem by cashing the king of hearts and exiting with a trump. West wasn't sure what to lead next. He finally chose a diamond, which would have been best if South had held A K J 8 7, A 7, K 6 4, K 10 3. (True, he might have played differently with that hand.) South won with the ten and claimed 12 tricks.
Let your opponents make the mistakes. Let them excel at someone else's table, not at yours.