A good cover is something that catches the eye. Something that isn't like everything else. Not too flashy, but just enough flash. The title? It has to fit the book. Sometimes using a keyphrase out of the book is perfect. Other times something that describes the overall feel of the story. Whatever it is, it needs to be relevant. I, personally, as a reader, don't pick up books with vulgar titles. I just think it's tacky. The title NEEDS to set the tone for the book.
Great dialogue. If it's stilted or unrealistic--meaning if it's not what you'd say to someone or how you'd say it, it throws the reader off, at least it does me.
