I have heard time and time again that it is helpful to print out a physical copy of something when editing. I was reluctant to do this for a long time because of the cost involved. However, this past week, thanks to a friend sharing her discount, I printed out my entire manuscript, had it three-hole punched and put it in a binder. When I sat down to revise I started at the beginning again rather than about one-third of the way through it where I was. It's amazing but I immediately found things I wanted to change that made the story better and perhaps even stronger.
I've heard that the eye sees things it misses while reading a paper copy rather than reading and trying to edit on a computer screen. I have absolutely no idea why that is and the opinions about it seem to be varied. However, I can say that editing on paper is definitely working for me. Even more of a revelation to me is that I am actually enjoying the editing now. Hopefully that continues and I can get through the revisions more quickly then get this manuscript finally submitted.