When I get down to serious editing, I actually don't edit the manuscript.  I rewrite it.  Kind of like Rick's version above only taken to the extreme.  Since I use Microsoft 365, I open the original document and a fresh blank.  I slap the finished to the right pane, the blank to the left and I start all over.  I read from the original and type it into the blank document.  Only now, I can see all the little mistakes I've made (my big hangups that drive me nuts are thing/think, and adding an 'e' at the end of 'th' words).  This lets me see the story that I wrote from the perspective of knowing the exact ending, the exact journey to get there, and the exact character changes that go on.  Not only can I tighten up my dialogue, description, and text, I can add more foreshadowing and other tools that will enrich the story.  And instead of reading and typing and backspacing and slapping myself in the head, I just write the story anew, with a great template to guide me.

I don't know if that will help but it helps me a lot.