I've got plenty. No, I'm not talking about biting my nails or leaving the cap off the toothpaste (I may or may not do that). I'm thinking more like tenses, commas and repetition. Last year at this time I had no idea just how hard writing was. I've always had the plots and stories in my head, so I thought all I had to do was write them down. Was I in for a shock. I'm not a complete novice when it comes to writing and editing. I have a degree in journalism, so I've had my fair share of English and writing courses. But even that background couldn't prepare me for the rigors of a PROFESSIONAL EDITOR!
When I got the first round of edits back on my first book I thought maybe I had chosen the wrong profession. I had no idea just how many mistakes I had made. I was in a panic and totally embarrassed. My publisher offered me some really good advice. She basically said no one is perfect and if we can learn to correct one mistake a book we're good. I thought, hmm, it's gonna take me twenty books to get this thing figured out.
Run on sentences, POV switches, show don't tell, comma usage, dialogue tags, repetitive words... does it ever end? Yes, it does. With each set of edits I learn something new. My writing does get stronger with each book. And, I think my editors may want to scream a little less when they open my manuscript for the first time (at least I hope they do).
Study your craft and learn from your mistakes. It'll make each attempt at a new manuscript a lot easier. It also makes writing much more fun.