What's key, in my work these days, is to leave behind the copyediting, subediting, and to think in terms of big picture editing. I'm a capital "E" Editor now.
An assigning editor at a famous children's magazine told me of her exasperation after one of her staff had copyedited the same text in three revisions and kept finding errors. "Stop looking for mistakes!" she yelled. "Think like an editor and just let it go!"
I believe I've discovered my new mantra: Just let it go.