$200 NL at UB. Villain and I have mixed it up a bit. I raised a river bet when a flush hit and he called and had the flush and I didnt, so he may think Im a bluffer. (I did have TP on the flush hand). He called the flop with a flush draw. Then he made a 1/3 pot bet on the turn when it was checked to him (not by me). I called his turn bet. The flush hit the river and he bet $12 into a $70 pot. I raised to $50 because I thought he was blocking. It wasnt a good play.

So on to the hand.

He limps and I raise to $10 with [8s]. He calls.

Pot $23. Flop [8c][4s]. He checks, I bet $20 and he calls.
Pot $63. Turn . He checks, I bet $32 hoping he will chase the flush if thats what he has. He calls.

Pot $127. River . He checks. OK, if he had the flush draw, hes not calling anything so it doesnt matter how much I bet. I need to bet what i think he will call with whatever else he might have besides the flush draw. How much? What do you put him on?

IMO he can have straight draw here too and something stupid like A9.
I would probably bet 50, hoping for a call from a 9, or a J (if he has JT).