ooookay, first, scrap those trees, they look very unrealistic, I'd recommend taking a close look at all the threes in UTM and picking the ones that best suit your angle, the glow models on the top just don't fit, I really don't see why they are there. It may look better if you remove the generic skies, add a stormsphere and some clouds, then play around with the tints (including fog tints). Also, If you are going to use a sun you should make it a bit smaller (you could use sun flares instead of glow if you wish). Fix those, and let us see what happens