Join a writing circle, where you share work with others. It's really helpful to get early feedback. And read lots. Read outside your genre. (You're probably already reading books in your genre. You've got to do that too.) Don't try to get on the bandwagon of what's popular! In most cases, by the time a book hits the shelves it's already two years since the writer sold it... so whatever bandwagon you might want to jump onto, it left the station long ago.