I don't take control of pots where betting as a bluff is correct, I bet as a bluff because I have air on the river and I was the aggressor. This means that I miss good opportunities to bluff, and I bluff in spots where my opponent has a hand he wants to take to showdown.

I'm starting to think that I shouldn't bluff without reads. Of course that's probably wrong, because there are some spots where even fish would fold because my line looks so strong.

For example, I had a hand where my opponent's range was small underpairs and AK unimproved, because I cbet the flop, checked back the turn and he led the river for 1/3. I should have raised him as a bluff for sure because he can't call a river raise with his range. Of course, having checked back the turn is problematic because if I had a good hand (and the river was a blank) I would probably not opt to pot control due to the straight draw. Although my line would semi-make sense with TPTK worried about sets.

tl;dr how do I pick spots when to bluff, other than when my own range look strong