In play money games, you can work out strategies for various spots without risking real money. To do this, you just need to play and screen spots of difficult situations in the game in order to analyze them later in poker programs and calculators.
It is better to do this at fairly large stakes, because there will treat game chips more carefully. For example, i'm pretty good at seven card stud and recently started playing it on play money at 10k/20k stakes with a starting stack of 500k. So, they play so carefully there that i have not yet been able to beat this game )))