Wild West towns tend to be 2 parallel rows of buildings on one or two streets, outhouse alley behind the rows. Almost all buildings are normal peaked roof buildings, but have a facade on the front that make it look larger. Need to put it on a stream or river, unless there's a good well. Desert southwest towns are more made of adobe mudbrick, while most other areas are wood. They are pretty simple really. Really big towns/cities might have a small grid of city blocks with streets surrounding, but not typical of smaller old west town designs. Follow the terrain, keep roads straight - simple.