As with any game of pure chance, there is no real effective strategic system for winning at slots. You will probably, of course, encounter someone who claims to have developed thefool-proof' slots strategy system but please, ignore such advice. The outcome of slots is accidental. The machines have no memory, so there is no effective way of outsmarting them. The strategy can be represented only by a number of tips. Try to find something above 95%. Similar to other casino games, it is crucial to know the odds and probabilities of the machine you're playing. There is a payout table for each slot, so make sure you read it before inserting coins. Determine your losing limit for the day. Stop playing when you reach this losing limit. It is not wise to think that you will be a winner all the time. You will lose too. The machine will not feel bad if you spend a lot of money and don't get anything back. Try not to spend all of your time on a machine that isn't paying out. If the machine pays out good you’d better make higher bets. Make lower bets if you are slumping. Play the slot machines that your bankroll can afford. If you have little money you’d better paly dollar machines. Don't forget to cash out the credits you've accumulated. Sounds obvious, but a lot of people forget! Never make high bets if you play slots you have never played before.

You must know exactly the game you are playing.
You should know exactly how many coins you are supposed to insert into a machine. Your credits should be cashed out before you leave the machine.
Only if you have fun your gambling won't be stressful. Use money management. Increase your bets when you are winning, and decrease your bets when you are losing.