The result of each spin is determined by a computer program even if you are playing the game online or in casinos. There are machines that reward you for playing the maximum number of coins. If you for some reason do not want to play the maximum coins you can move down to a machine that accepts lower value coins.
A good strategy when playing slots is to try to change your bet size. This gives you the chance to win more money and if you are lucky you can hit the higher pay-line when you are on higher bets.
Important things to be kept in mind:
you should know where you stand at all times do not play credits play coins and this way you can always track where you stand do not accept to play just any machine, learn what machine is better for you and stick with it always try to achieve more and do not be afraid of playing on high end machines even the 5.00 slots.
All this is also true in the case of online slots, but there are also some extras to your benefit, you have a greater variety of games, and once you get bored of one you can simply click through to another.
Maybe you will loose in the beginning but the more you play the better you become.
Don’t be afraid and try it, unless you are afraid you might get addicted to it.
May the Goddess of fortune be with you!