Attached Link: http://www.ocddoug.com

In my opinion, I think you should put some bump on the trees. Maybe a little fog or haze will give it a more mysterious look. I feel like one of ocddoug's atmosphere might be applicable to this setting. He has some free stuff here: http://www.geocities.com/bookjunkkee68/index.html Ultimately it all depends on what look your'e going for.