Every player must stick to his bankroll. Bankroll is the total amount of money you can afford to play with or to lose. There is a bet max button on every slot machine. Bet Max button allows you to play with the maximum bet on this very slot machine. Comp is so called additional bonus, which is given to the player who has been playing one and the same slot machine for quite a long period of time. Comp can be represented by free meals and in come casinos by money rewards. The percentage amount of the house edge indicates how much the casino wins from every bet over a long period of time. Payback is percentage amount of each bet dollar, that is paid back. If you play the slot machine with 86% payback it means that it pays back 86% and 14% is the house edge. Remember that these amounts are taken over a long period of time.

You must know exactly the game you are playing.
Only the correct amount of money should be inserted 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. Be smart and change oyur bets according to your luck.