The whole c-bet landscape has changed a lot last few years. It's still valid but the big change has come in how people respond to it. You will no find it more difficult to collect a pot with a single c-bet as floating to the turn and beyond is happening with greater frequency. This means you can't afford to look at just the flop action, you have to make sure to think beyond as to what you are going to do on the turn also (as well as the river). So to just throw a c-bet out on the flop with no plan for later streets would be unwise.
And what is that plan? Well it totally depends on your opponent and the board texture. If that flop was super dry and your c-bet gets called you have to be very sharp on ranging your opponent as the odds
of him making a move on you on a later street goes way up. He just assumes you missed and is going to pressure bet you to fold on the turn if a scare card doesn't pop up. He doesn't even care what he has, he's convinced you are screwed.