I'd heard about that point in the final editing process where you'd rather set your head on fire and put it out with a sledgehammer than read your mss one more time. I hit that point about four years ago, but I tried to squash my indifference and focus on the task at hand this April with Star of Justice.
Considering what I've found, I failed miserably in the squashing and allowed indifference to win out. So I'm making a checklist for the next book.
1) Run spell check on the entire document. Especially important for made-up names. Just be sure to spell them correctly the first time. This brings me to the addendum to 1): pay attention to spell check while running it.
2) Run grammar check on the entire document. This one will have you banging your head over every fragment of dialogue, but it will catch some (few) things. Not as many as you might hope. I also never trust it's suggestions, but it's a good way to make sure you're saying what you mean to say.
3) Run "find" for everything you can think of, in an orderly fashion, with a checklist. In fact, 1) should probably be "keep a checklist of things to check." Extra spaces, extra punctuation, words that should be italicized or capitalized. Words that shouldn't be italicized or capitalized. If you think of it, write it down and "find" it. Every time.
4) Keep a list of things to check and check them off when you've checked them. I found a couple of things I meant to check or change, yet apparently failed to check or change. Do you know how irritating it is to think of doing something and fail to actually do it? Yeah, you probably do.
5) Read the entire document (yes, I mean that) in a format other than the one you normally use. Really read it, too, not just skimming. I spotted the missing period while reading Star of Justice on my Kindle. Stupid me failed to note the spot, and despite my best efforts, grammar check and "find," that period insists on remaining missing. I figure it's God's way of humbling me.
6) I'd say ask someone else to help, but, frankly, I'm the best judge of this kind of little, piddling stuff. I'd rather save my friends for bigger issues like content and clarity than waste them on comma searches. I love you guys that much. You're welcome.
That's what I've got so far. Feel free to add any suggestions I may have missed. I am once again forcibly reminded how fallible I am. I'm also inclined to run grammar check on this post.