No, there are no surefire ways to win at slot machines. These games are based on random chance, with each spin being independent of the one before it. Because it is difficult to foresee or manipulate outcomes, the best strategy is to play for fun and set a budget to avoid financial losses.
It's all a matter of chance. There are no blackjack- or video poker-like strategies that can cut into the house's mathematical edge. Odds on slot machines are unchanging. There's nothing you can do legally that will change the outcome, though scam artists sometimes have succeeded until caught, arrested and imprisoned.