just looking at this and seeing where you want to take it. I grab a book my better half has on oil paintings, so far you have got the tone of the image right..the lighting, colours and feel of it gives it that oil painting look.. Add a rock like jfike mention you could also try adding a dead tree in the background over the back of that mound of rubble just to break the openess it has there a bit. Just my little bit of imput i hope helps.

I have opinions of my own -- strong opinions -- but I don't always agree with them.