There are plenty of books around which a good poker player should read, no matter whether you are a beginner or advanced player. I have collected here some of my most obvious mistakes which I often se in many casinos.

Do you see those idiots calling all the way to the river, and the win by some “harakiri-draw”? Do not complain if they win with bad hands every now and then. They are the ones who pay you. Make sure that they enjoy playing. Give them a comments that are positive and make sure that they don’t leave the table. You are giving away information about your level of skill. If you make them mad and they begin to play better, that can also hurt you. Don't chat. If someone admires your skills just say “thanks” or TY. The Zen of good poker is that it is played in silence. Every word from you is valuable information for your opponents.

My biggest fear is that when I see a loose player is that he/she will loose the money to some other player. That’s why it is important to keep the fishes playing with you as long as possible.

Add loose player to your Buddy List
This is a pretty popular tip used by many of the good players on poker sites. By checking your buddy list off and on, you can see when your favorite is playing or not.

This tip is mainly useful if you are adding maniacs to your buddy list, as maniacs tend to create table dynamics that are much better for you. With a maniac at the table and some loose passive players for example, there will be serious pots being generated.

Fear and greed

It is said that fear and greed cause everyone to expose their true nature at the poker table. Think about this and then decide what part, if any, you want to expose.
Information that you gather about your opponents helps you, information they learn about you helps them. Don't just give it all up for free.  In tournaments, especially in the latter stages, keep chat from the rail to a minimum.