MVPeanaught

Here's a reference where you can see what I mean: https://www.artstation.com/artwork/Nez8b Basically how do I create a transparent plane that I can paint on? I also want to bend some planes with minimal vertices like the tree leaves, should I just use blender for that or can it be done in 3DCoat? Also can I make my own brush alpha inside of 3Dcoat? Thanks in advance