I think that the main thing that you're missing is some cool patterns...these are pretty simplistic. While there's nothing wrong with that, you obviously want to kick it up a notch. Browse through the Mapping Elements section and follow the links for different pattern websites. There might be some in the Reference Material section as well, not sure. You could also just do a forum search for "patterns" or something. As for the little buildings, have a look at the Dunjinni user forums, there's a ton of cool lil roofs there.