Beginning players often have trouble making the right sized bets, especially to take home a pot. A lot of beginners will go all-in -- which is fun, until someone calls you and turns their pocket aces. Why risk your whole stack when you only need to bet a fraction of it to win the pot?

That fraction is just enough to make calling unprofitable. All good players use a concept called "pot odds?" when betting; you just need to bet enough money that their pot odds become unfavorable. Are you heads-up against an opponent with, you'd guess, AK or KQ, while you have JJ? Well, your opponent is about 45% to win that pot. Don't give them that chance; win now. Bet 50% of the pot and a good player will see that they don't have the right pot odds to get in and will fold.

This works even on poor players, although they don't know about pot odds. The reason that good players use pot odds is that, by taking advantage of this concept, they'll end up winning money in the long run. If you're playing a bad player and can make them make bets with bad pot odds, they'll end up losing money in the long term. If they're betting against you, they'll lose that money to you. This is poker; take their money.