That mjrananum green girl on the vine swing is becoming her own meme...Interesting image, but the lighting of the shoe (LH top) does not match the tree (RH side), nor the cow (RH top)...It does match the green foliage on top of the tree, which is also reversed, though...
You may want to try adding some highlights with the Dodge tool at low opacity on the RH side, or flip the shoe. If you reverse the tree and the shoe foliage, the image will look more consistent than at present...
Light source direction is an important consideration.

Very interesting entry, GL!

I would suggest for future work that you spend a bit more time on your masking. It will help refine and enhance your work. It is a pain to get it right but worth the effort.

It all starts there, no matter how good everything else is, if you have left-over pixels, smudgy bits and outlines it can ruin a great image. You idea is very good, your masking needs some more work. To get you going try checking out this tutorial on how to mask trees ... hope it helps http://www.pxleyes.com/tutorial/photoshop/1272/How-To-Mask-A-Tree-In-3-Minutes.html