Bad news: there is no formula for creating an awesome LEGO castle like this one. Although Igor Elshin (Sunder_59) built this model more by feel than by a set of rules, he was able to share a few pointers with me.
Looking over Kazum’dar Castle from a bird’s-eye view, I was impressed by the clean appearance of the model. So I asked Igor, “How do you keep from over-complicating your micro-scale builds?” Read his answers below.