“…remove words in such a manner that no one would notice that anything has been removed”

…remove words in such a manner that no one would notice that anything has been removed. Easier with some writers than with others. It’s as if you were removing freight cars here and there in order to shorten a train—or pruning bits and pieces of a plant for reasons of aesthetics or plant pathology, not to mention size. Do not do violence to the author’s tone, manner, nature, style, thumbprint. Measure cumulatively the fragments you remove and see how many lines would be gone if the prose were reformatted. If you kill a widow, you pick up a whole line.

John McPhee, “Omission”, The New Yorker (14 September 2015), 47.