Every player makes these mistakes at the start. The good news is that they are easy to recognize and, once you see them, hard to forget. Fixing just the first three already makes a big difference to your results.
1. Playing too many hands
It's mistake number one. Every hand looks like it could work out, and seeing the flop looks cheap. But each weak hand you play creates difficult spots later: pairs with a bad kicker, draws that don't come in. Start by playing fewer, better hands. The starting hands list is a good place to begin.
2. Calling too much
Calling is the most comfortable play: you don't have to decide whether you are ahead, you just see what happens. But calling never makes your opponent fold. If your hand is good, raising is often better; if it's bad, folding is cheaper. Call when you have a reason, such as the right pot odds.
3. Ignoring position
The same hand is worth different things in different seats. Playing K-J from the first seat to act is asking to be dominated; from the button, it's a good hand. See Position in poker.
4. Falling in love with your hand
You were dealt A-A, raised, and now the board has four hearts and your opponent goes all-in. Pocket Aces are the best hand before the flop, not after every flop. Knowing when to let go of a good hand when everything says it's beaten is one of the things that separate beginners from experienced players.
5. Bluffing players who never fold
A bluff needs someone willing to fold. Against players who call everything, bluffs become donations. Against them, bet when you have the hand and let them pay. More in How to bluff.
6. Betting differently depending on your hand
Betting big only with strong hands and small only with bluffs is an easy pattern to read. Use similar sizes in the same spots, whatever you hold. See How much to bet.
7. Playing on tilt
Tilt is playing worse because of emotions, usually after losing a big hand to bad luck. A player on tilt gets into bad hands to win back what they lost and calls bets they shouldn't. If you notice you are playing angry, take a break. The table will still be there later.
8. Judging a play by its result
You went all-in with A-A against K-K and a King fell on the river. Was it a bad play? No: you had an 82% chance. In poker, good decisions lose and bad decisions win all the time, hand by hand. What matters is what happens if you repeat the same decision hundreds of times.
9. Forgetting what the board can make
It's easy to look only at your own cards and get excited about a high pair. Before betting, look at the board: three cards of the same suit? Four in a row? A pair on the board (which allows a full house)? Ask yourself what hand your opponent would need to bet like that.
10. Not paying attention to the others
Each player has a style. Some only bet with strong hands, others bet at every opportunity. When you are not in the hand, watch: who raises a lot, who never folds, who showed a bluff at showdown. That information is worth chips in the next hands.
The fastest way to learn is to play lots of hands without fear of losing. With virtual chips, a mistake only costs virtual chips, and Pokerzin gives out free chips every day.