Camera location is pretty random. I let the preview update from a high observation point of view. If something looks like it has the potential for the scene I want, then I zoom in. Next I set the camera and do a quick, small render. The terrain get altered to make things look more interesting. Then I start doing my surface shading. Atmosphere, and objects.
When I look at other peoples images, I like to guess what the landscape looks like 'plain', without shaders and objects. Most of the really good images, at the start, are pretty boring looking.
