I like your line and the faces, also very good detail to the backgrounds! I know what you mean about having to do some pages before doing the story, Some writers do that, in order to start knowig their characters, and is a very good exercise, so the story can breath, born, and, in some cases, tell you what it is about. For some, the stories need to do this in order to exist, others like to plan before, but really, there is no a single way, only the way that works for you. Perhaps doing the pages more rough would help to save a little tiem, but what works for you is fine, in my opinion. good job!