The Editorial Mindset
I've always appreciated Stephen King's advice on writing. So much so that I once bought a jacket with a tiger on the back because he suggested that it was a good way to build confidence as a writer1 (see George Stark in The Dark Half). Another piece of advice from King is this handy rubric for editing: "cut 10%"... or in the words of his high-school era editor:
“Not bad, but PUFFY. You need to revise for length. Formula: 2nd Draft = 1st Draft — 10%. Good luck.”
This is solid advice, but as you might guess there is a lot more to editing than making things shorter.