Well I suppose we need to differentiate between rescuing something with PP and taking a 'correctly exposed' and composed image and modifying it to get the effect we desire. The important thing is to make sure that the raw files contain the right amount of shadow or highlight detail that you wanted, is focused as you wished (whether sharp or not), displays movement blur or not and has the amount of DoF you need. Then you have the right starting point to go, however far that might be.