Stage two: Edit it yourself. You can do this any way you like, but I find it really useful to approach it in rounds that more or less mirror the editing process at a publisher:
If so, that's fine. That's GOOD. You're working on your book to make it better. Making your book better is awesome, and you should feel badass and excited about it.
You're pretty happy with the shape of the book. You think you've made it structurally as good as it can be, and you've infused every scene with as much power as you can. The story itself is as good as you can make it.
I strongly recommend not fiddling around too much at the line level before this point. It sucks to perfectly polish a scene and then wind up cutting or rewriting it. Save the line edits for last!
They may give you feedback on things you can improve, and can help you brainstorm ways to fix it, but you're the author and it's ultimately up to you to do the work.
START ALL OVER AT THE BEGINNING OF THE EDITING PROCESS.
You get an edit letter and also sometimes a phone call, talking about structural edits the editor wants you to make to your book.
DO NOT BE SCARED. This is good. No, really.
Again, the work is all up to you, the writer, though. You have to decide HOW to make it better, and then do the work.
Yes, this is after already polishing the HELL out of that book.
Even here, you can choose to let things stand (stet).
Editing is a HUGE part of writing!