Lets list them!

#1.) Raising someone's blinds so much that they hate me by the end of the tournament. Now that they hate me, they play back at me, and I lose big pots.

#2.) Long, drawn-out, elaborate bluffs that almost never work. Sometimes I get attached, and I can't let go, I'll c-bet, then plug the turn with nothing, then there's so much in the potby the river that I try "one more", and it costs me a huge pot or my tournament.

#3.) Reacting too quickly, must slow down before I click my mouse sometimes

#4.) Bullying with the big stack. The few times I am a big stack at the table, I get overly aggressive, thinking I can just run the table and go over the top of everyone.. this doesn't work when your opponent is unwilling to fold top or 2nd pair.

#5.) Raising small bets with nothing.. you know the weird 20% of the pot bets that people make online.. I've found more often than not they want you to call and they just don't know what they're doing.