"Discrimination and self-discipline"
“Two of the most valuable assets of any photographer are discrimination and self-discipline. The first is the ability to distinguish between photogenic and unphotogenic subjects, to know what will make effective pictures. The second is the ability to have will-power enough to resist the temptation to “shoot” when a subject is graphically “hopeless”. Specifically, if the illumination does not seem right - as effective as it could be - and there is nothing a photographer can do (as often happens when working with daylight), he will forsake the shot rather than bring home a picture he can never be really happy with, because no matter what, he always has the choice to select or reject.”
Andreas Feininger