Always Have Fresh Eyes Looking

You can only read something for the first time once. Once you've done it, you've been forever changed. More than anything else, it means you can't read that piece the same way ever again. This can be a difficult challenge when revising your work.

You always need a fresh set of eyes looking at your work. Every time you have a new draft and you think it might be good enough to be a final draft, you need somebody new to read it. Your editor can be the best editor on earth, but if they've seen it and they've worked on it with you, they know it. They know what it used to look like. They know what it is you are trying to do, and it will bias their reading. (If you ever tell a reader that "What I was trying to do is X, does that come across", then that well has been contaminated.)

The general public will probably read any given piece of writing once at most. Your first impression is absolutely critical. They won' be studying it and mulling it over and working with it. They will suck it down, and either absorb it or spit it out. Your editors and readers are no longer the general public. Their views and thoughts as supporters can be beneficial, but their value for a first impression is zero after they've read it once. Keep that in mind, and have a short list of good readers.

Remember that you only need a fresh eyes if you think you have a final draft. If you're still on the drawing board, a good editor will still work just fine, no matter how many times they've seen it.