See also
There are two major postflop basic strategy position plays that cover the majority of the postflop situations in which you have position on your opponents. Here are the two secret strategies for making money after the flop:
1. He checks, you bet
2. He bets, you fold
That's it. If you've played in a few tournaments already, then you know this is no big secret. You see it all the time. But do you do it? You have to do it! In fact, about the only time you shouldn't bet when your opponent checks is when you've flopped such a monster hand that you want to give your opponent every possible chance to make something so that he'll be willing to put some money in the pot.
Let's dissect the logic of these two postflop strategies.
He Checks, You Bet.
He-checks-you-bet is just a standard basic online poker strategy play when you have position. Standard. Requires no thought. Just do it. As your skill level increases and you begin to get meaningful reads on your opponents, you will occasionally make an exception to this play but don't make a habit of violating this strategy.
If your opponent didn't bet, it is far more likely that he disliked the flop than that he is slowplaying you. About 90% of the time, the routine is: He checks. You bet. He folds. Forget about the 10% of the time when he is either slowplaying you, or likes his hand just enough to call, or has a strong draw and wants to see the next card even if he's not getting sufficient pot odds, or just thinks you're taking a position shot and is determined to be the sheriff. Unless you have some kind of an actual read on your opponent, ignore these possibilities. Follow the basic strategy.