I am in awe of all Ana' efforts. I confess I don't do anywhere near that much editing.
I edit on a daily basis, editing what I did the previous day. This way it keeps the story and characters fresh in my mind. When the novel is finished I leave it for a couple of days and then return. I read and edit as I go along.
There are many excellent "professional" editors out there who have helped me on the way. I don't see myself as an "Editor" The senior editor at Whiskey Creek Press, is a marvel, Marsha Briscoe really knows her job and she misses nothing. I do, I am too rapt up in character and story, the technicalities quite often pass me by.
Perhaps there is no right or wrong way to edit. We are after all individuals, we all work differently. That's why our stories are different!