Vampires want blood~zombies long for flesh~what do your characters want? In order to connect with your story~ the reader must know what drives the main characters. Why does your villain do cruel things? Is he striking out in pain~seeking revenge or truly evil? Why is the detective determined to solve the case? Is she motivated by ego or is there a personal connection to the victim? Why is the teen in your YA novel determined to date his/her crush? What’s behind the attraction?
Give your reader characters that are lovable and horrible by showing a bit of their soul. Share the driving force behind their actions. Motivation creates connection between reader and author.