Character development is a higher priority than plot development for author, editor, and ghostwriter Kathi Macias. She always knows where the book will begin and end, but isn’t clear on what will happen in between. That’s because this part depends on the characters, so Macias devotes more time to developing and getting to know her characters. She uses a method that is described in her book, The Train-of-Thought Writing Method, which calls for authors to know the ins and outs of their characters, even if all the details won’t be mentioned in the book. For example, Macias believes authors should know what music a character would listen to in the car, or what he or she would buy at the grocery store. Thinking about these details helps bring characters to life and make them more three-dimensional.
I have to say that I can totally relate to not knowing what happens in between the story. I focus on my character and as they develop my story develops. I hate thinking about what will happen in each chapter because it constantly changes as I write.
I would try writing at least a rough outline, just to give yourself a rough idea as to where you want your story to go.