Many gambling writers will claim that you should play with maximum coins but it's better to play with one coin in higher coinage thaen a few coins in a lower coinage, when coinage is higher the casinos return a higher percent of the betting as coinage is higher.

Another tip is to make sure you empty your machine when leaving it making sure there are no credits left because there are many vultures out there waiting for the oppurtunity for you to be out of focus so they can jump on the machine and clean it out.

Make sure that the percentage of payback that is indicated on the machine, always read the small letters(in everything) because for example if a machine has a sign "%98 payback" t doesn't mean it applys to that machine.

Most importantly always be alerted and test out your luck, don't expect anything - the more expectations the more you can get disappointed.(this advice is good not only in the casino).