The truth is that there is no trick to slot machines. They provide random results based on set mechanics and it all comes down to luck. With that being said, not all games are the same, so picking the right options is key, and you can still change the size of the bet throughout the session for better results.
Therefore, there is no way to predict when a slot machine is going to hit, and any strategy or system claiming to do so is likely to be based on superstition rather than fact.