Attached Link: http://www.geocities.com/asperen290573/tutorials/tutorial6.html

It's a beautiful terrain! And yes, the eagle stands out a little bit too much. The spiked terrain for trees is very difficult to manage, you can try the foliage presets. I also think that turning down a notch the mountains ambience would make them look even more dramatic than they already are (but maybe it's me, I have to admit that I don't like ambience at all, in my pics I tend to set it to zero and then playing with the general ambience value).

As for the sky, you can try applying a 2D pic or, even better, trying the beautiful tutorial by roobol you can find in the off-site Bryce tutorials section. (The link is above).

Stefano