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.

SLOT TIPS: THE DO'S

Higher denomination slots have higher payback percentages.
Make sure you bet enough to be eligible for the jackpots.
Choose games that fit your goals and playing personality.
Always play within your budget.
Start small to win big, or prime the pump 
Play machines at the ends of rows.