I actually hate this image, I decided to do something different of what I use to do, and went for a fantasy/dreamy image, and most of it was really painful, some things I just couldn't get right, so, most of it was just "f*ck it, I'll figure it out in post processing".
But yes, I really learned a lot (and that was the main idea), especially on post processing, I know it's not good, it has it's terrible flaws, but at least I could get something publishable (I think).
Third party stuff I've used:
Grass Free addon from 3D-Wolf
PBR Materials 3 from 3D-Wolf
"Bricks Lumpy" material by Game Textures
Trees by xfrog
WaterBeauty by Shimoon (BlendSwap)
"Black Hole" Material and Stars texture by Gleb Alexandrov
"Jelly" material by grs (BlendSwap)