I think that c-bet, becomes an art that depends a lot on the variables that play at that moment: position, type of players and number of players in the hand, the strength of our hand and the type of flop, if we were the that we opened PF or those that we did check, etc, to be able to make the best decision.
I also think that the c-bet is more automatic in the cash games than in the tournaments, where the environment of the hand is analyzed more.
The bet sizing, is a very important issue when playing after the flop, varies depending on many factors and is almost always determinant, we must change the bet sizing to not be easily read.