One of those "a-ha" moments cash players often have is related to betting when they're ahead. More often than not, the lesson is learned by slow playing a hand like two pair or a set, and then getting sucked out on by the opposition. It's a hard lesson to learn for some (ahem, like me), but learn it we all do eventually. When you think you're ahead of the range of the opp, bet. Unless there is a damn good reason to do otherwise, bet you hand. Make the opp pay to see another card.
When we bet, we're essentially saying to the opp, "I think my hand is better than yours. Here's some money to back that up. If you think your hand is better than mine, or if you want to see more cards, then you have to pay." Poker really is based on this premise. It's not based on the premise of "I think my hand is better than yours, so I'm going to slow down and limit the amount of money we get into the middle on the early streets. I hope you don't suck out on me."
I stacked a player today when he slow played a monster. I had KQo on the button and raised 3xbb when it was folded to me. The SB folded, but the BB min-RR'd me. His numbers suggested he was a bit of a LAG, so I called, hoping to hit and get paid off by way of his innate aggression. Against a nittier player, I probably would have folded, but in this situation I would have position and an easy-to-play hand post-flop.
The first three cards came JT5 rainbow. He checked and I checked behind, afraid of a CR, and preferring to take a free card than get into an altercation with a player who showed aggression PF.
The turn was a 2. He checked again. I figured now that he had a hand like small to middle pair and was afraid of the board, or maybe had AX and was shutting it down. In any case, when the opp checks twice in that situation, I tend to bet out, so I fired about 75% of the pot into the middle to see if I could take it down. He smoothed, which made my warning bells go off. Okay, I thought, he's got a real hand or at least a strong draw.
The river was a glorious rainbow Ace, giving me the nut straight, and, hopefully hitting his hand, too. He purse bet into me with something like 25% of the pot. I figured he thought this was a value bet, so I RR'd it with a pot-size bet. He instantly shoved all-in, and of course I insta-called. The opp turned over TT in the hole for the flopped set.
I added $12 to my stack on that last hand of my session and sat out. The opp also sat out, but he started berating me for playing such a crap hand, and chasing the draw, and being a donkey, and questioning my ancestry, etc. Uh, okay, I thought. You priced me in, and let me see some cheap turn and river cards. I think I played the hand well, and I think you played it poorly.
Instead of saying that, however, I simply logged off and counted my money. He will learn the lesson eventually, but it's not up to me to spell it out for him. My job is to teach it to him by just taking his stack and moving on.
All-in for now...