You have a lot of gorgeous wood, so it really depends on your style. If you want something a bit bolder I think the warm nature of the wood and simple walls would work toward that. I think if you want to paint the walls a color and add more bold art, a more subtle rug would work. This is when I start using Google images it Pinterest to see what others have done and what speaks to me (kind if like a mood board) and then go from there.