There is a specific reason artist who make money use reference to make anything look "real-istic". Unless you are going for the "completely made-up" look or the classic "I am never going to get a job as an architect" then learn a lesson from this "study" as I am, slowly!
Always take your time to sketch-out your drawing before you go to paint, for no other reason than to be sure that the layout works for you. Think about it like this, if it does not work in sketch form, however crude it maybe, it will certainly not work in paint, of any medium, unless your intention is otherwise.
