I think a better question is: what is the main thing growers do that keeps them from reaching the genetic potential of their grow and how can they avoid it? My answer would be harvesting too early. I see growers harvesting early all the time either because they've heard that you should harvest when you have 25% cloudy trichs, or you should harvest at a certain date, or even that they are impatient and want to smoke it now. You gotta go by trichs, you can find 25% or 50% cloudy way too early, don't harvest then. I never harvest with less than 25% amber trichs and that's an average taken from several locations around the plant. A real microscope, even an old school one, is a huge help.