How much editing is justified?

[Pieter12]

But sometimes I pre-edit my pre-visualization posthaste and not push the shutter button... .

And the would be editing, too.

 

[Vaughn]

And the would be editing, too.

My successful images have around 75% (totally guessing) of their editing done before I expose the film, though not 75% of the work. Unsuccessful images are edited out 100% except I can't throw negatives away, so they stay around to haunt me.