Start from the given generic landscape and change its “mood” without adding new models.
You can manipulate lights, skybox; camera settings, camera transform and effects, materials and textures, add sound and particle system, use scripts.
how to create a skybox
import settings and normals
automatic uv mapping / how to paint and uv map textures in mudbox
*Lynda has a tutorial on texture painting in mudbox.
**I added a microtutorial with the steps to create a skybox from found images