Don't love your main character too much.
That happened to me with the first 13 (!) drafts of Hattie Big Sky. I loved Hattie so much that I didn't want anything bad to happen to her. So I created a character named Ned who was her buffer against bad guys and tough times.
My gentle editor asked me what I saw Ned doing for the story. Ned! Why, he was wonderful. Charming. Amazing.
But, as soon as she asked me that question, I knew Ned had to go.
When I taught writing, I would tell my students to be kind and loving and caring people. Except on the page. Then, they must be anything but kind; they must make their characters suffer! I'd forgotten that bit of advice when I was writing the early drafts of HBS.
So Ned was removed, leaving Hattie to face the cold, cruel world on her own.
Which just may be why so many readers love her.