What are values

[Mike086]

If you want to push depth of field you'll need to shrink on of the big shapes you have going on. Right now your foreground guy is the exact same height as your dead beast thing. Shrink down the beast and keep him in that she value range and then increase the contrast on your foreground figure, maybe add a cast shadow over the bottom portion of his body like light is hitting his over some unseen object. Also the mountains in the distance should look less sharp and defined as they recede in space. Look up some of Loomis' books about drawing the figures in perspective.

Also, adding elements like other "dead beast dude" structures in the distance will help show the space receding.