To expand...my single biggest issue is firing into opponents where I don't know if they are a calling station or can fold a hand. I'm noticing more lately that so many weak players will call c-bets with Ax just to see a turn, since they don't have a read on me (common fish logic).

Of course, this is great when I hit. However, I probably lost 20-30 bb this morning firing second pot barrels into a calling station before realizing that he ain't folding bottom or middle pair with no kicker.