My stories build themself a bit like yours - they flow, from start to finish, and they form into shape as they do so. My subconscious is a lot smarter than I am. I don't see them in shapes, or in colours - I see them in moods, if that makes any sense. I have a goal for my stories, and they always get there, but they can take some unexpected and twisty paths in order to do so!

Speaking of stories - I have now signed up to TARDIS Big Bang. And it's all your fault. *grin*