The ground is just as important as anything else. I suggest taking three photographed textures and rendering each one separatly. Then make them 3 layers in any app that allows layers. Using the eraser tool, erase through to other textures in places that you want them.
Take a look at my latest scene to see what I mean. Yes, I cheat... but who cares; it works.

http://www.renderosity.com/mod/gallery/index.php?image_id=1795877