Forest

This is really pretty, your use of colour is spot on; the orangey background and dark foreground give the piece a nice sunset type glow. I can see that you have used quite a few custom brushes, which is great for the most part! However, you should be careful of the image becoming too 'fuzzy' due to the soft custom brushes you have used. I feel it needs some sharper edges within the tree, which you have achieved in the top braches..but less so at the bottom.
Lastly, the foreground, middle-ground and background colours are great; it gives the picture depth. However, some more middle-ground wouldn't go amiss to enhance the feeling of distance between the back foliage and the front. Unless..this tree and lake is on the edge of a sharp downward slope behind the tree, I only noticed this after a couple of minutes looking. If that's the case then it's spot on!
Hope this helps