This is one area where I lose the most amount of money in poker because board texture doesn't give too many clues as long as the opponent's bets are sized correctly. Here's one example I faced today:
It was a 1/3 cash game. I had K4s on the button. One player raised to $15 and one called. A $15 raise was typically the minimum at this loose table. I decided to 3-bet to $45 as a semi bluff. One player called (not the initial raiser). The flop came K83 rainbow. All I had was top pair with a weak kicker. My opponent bets $30 out of turn. I thought that was suspiciously small so I decided to continue the story that I had a strong hand: I raised to $90. He called. The turn was a queen. He checked, I checked. River was a 7. Now he bet $150 out of turn. I stupidly called and he showed pocket 8s to make a set.
I know I violated the rule that I should fold to a big river bet if I can't beat the hand he's representing. But the way I justified making the call was he was asking for $150 to win a $450 pot so my bluff catch had to be right 33% of the time. And I caught him bluffing tons before.
My question is how could I have avoided the river call?
He made his river bet 1/2 pot so it didn't set off any alarms to me. I suppose the clues were that he called my 3-bet both times and then tried to trap me with a check on the turn.