The three most common mistakes I see from my new students before they have started working with me are:
- Playing too passive preflop, especially from the blinds.
Most players want to play it safe and see a cheap flop to see if they hit something first and then pile in money if they do. The problem with this is that if everyone tries to do that, there isn't much of an edge with this strategy. Plus, people will catch onto this and rarely pay you off. You need to be willing to three-bet for thin value to bloat pots or kick people out behind you to get into favorable situations postflop where you get to get all in by the river. This means you'll bustout sometimes in spots you could've 'played it safe' but its also the way you build up a huge stack and actually have a chance to win the tournament. - Not checkraising enough from the big blind for thin value or with their draws.
Players often don't do this for reasons similar to #1 above: they don't want to bloat pots and risk their tournament life. The downside of not doing this is that you won't get as much value as you can with some of your top pair hands, and when you have drawn, you'll often get blown off your equity instead of you taking the aggression and blowing them off their equity. - Not double-barreling enough vs. the big blind.
The big blind has an extremely weak and wide range, which means you should put a LOT of pressure on them and force them to have to continue with very marginal holdings. Most players only double barrel when they have some equity, like a draw; this is fine when you are out of position or playing against a strong range that has position on you. But when you are up against the big blind, you need to find some more unintuitive bluffs that you won't be able to figure out unless you are putting in some study off the table.
