Some of the practical advice that made my short list:
Writing is not something that can be treated like a Stairmaster.
Writing is not for the thin of skin.
Writing is not for the faint of heart.
Writing is subjective . . .
There is such a thing as “too much” editing.
Killing your “darlings” is a good thing.
Writing shouldn’t require wrestling with your editor.
And yes, it’s okay to let your editor go.
Writing a great novel does not guarantee you will be published or successful.