Usually when the aggro players slow down, that's when the little light should come on. Why is he not betting "this time". When someone peels a flop, this is the time to look at what they can call with. Are there straight draws, are there Flush draws? Is the board likely to have hit their range? If you have not hit the flop after raising, yes you need to C bet. But if you have AQo and the flop is TJ4 w/ 2 hearts, there are going to be a lot of calls. Think of the hands that call that flop.

go into PT and look at a ton of hands. Look at what the board looks like, what would you call with? Should you bet? mostly yes, but when they call, it's time to shut down without a hand, or draw. Also, if they are calling and your second barreling, what are you repping. If they call a K76 two flush flop and the turn is a 4hearts, would a K fold now? Don't just stop Cbetting, but start thinking about what? why?

If you use a hud, you may want to add the fold to C bet stat as well.