Every time I write something, different things run through my mind. The story is the first part of the focus, but sentence structure intrudes most of the time at a secondary level.
The big things are sometimes the easiest to figure out, but some of them slip through the cracks. It was the final edit of my novel to be published where I found a mistake about who was in class with whom. (While I hope that was the last error, we shall see when it’s printed and everyone else gets to read it.)
In my current novel project I’m identifying all the places where the protagonists interacted with others and making sure it’s all consistent with their personalities. Later I’ll tweak my verbs and check for overall readability.
It may not sound like much fun, but digging into the story to bring it out more is enjoyable. It also means my characters get to live on in my head while longer!