While I think you did a nice job with the screenshots you posted in the "Screenies" section (I especially like the cosmetic fog you used for the light streaming out of the windows), I think the ones in the "Map Screenies" spoiler could use a bit of work. They look too sparce, especially the last one that utilizes the Mountain tileset. I might recommend combining tilesets (or downloading something like the "Ultimate RTP Exterior" where a great majority of the sets are combined for you) so that you can diversify the mountains a little bit, instead of having to use the same tiles over and over again.
Some of the best forest/mountain maps I've seen make use of the following things:
-Added depth through the use of several layers of mountains that are staggered so as to look more natural.
-A nice variety of vegetation (combining tilesets allows you to use a greater variety of trees, shrubs, and flowers)
-Good use of water (natural looking waterfalls behind trees, round or diagonal autotiles... you can find a
really nice selection here)
All of these things can help make your larger maps less sparce and more realistic. Hope this helps
