The Ground and Mushrooms: I used the Pen Tool to cut both out. For the ground I used the Warp Tool and then duplicated it multiple times to get the look I wanted. I then played with the hue and brightness in the final image. The mushrooms I basically left the same except for changing the hue and adding some shadows.
step 2 of 3
The Tree: I used the Pen Tool again to cut out the log I needed to create the tree. I then duplicated it several times and warped it to get the shapes I wanted. After making the basic trunk, I duplicated that a few times and placed it in a way that made it look wider. Then in the final image I used the clone stamp to get rid of some repeat patterns and blend it a bit, and I also added shadows and changed the hue.
step 3 of 3
The Lake and the Sky: For the lake I just blurred the entire source image and overlayed a gradient. The sky photograph is one of my own.