Digital Hijinx, Photoshop
Obviously there are a lot more steps in the creation of this (or any) painting but I think these six images give you a basic idea of the usual process.
Just having a little fun with this guy
Here's a closeup of the work being done on this piece. As an artist, I've always enjoyed seeing the processes that other artists go through so I thought I'd start including some of those steps.
This is my basic setup. I try to maintain a pretty consistent range and placement of my paints so I don't have to try and remember where each one is on my palette. Off camera there's another 200 brushes and at least as many tubes of paint - I never want to run out of any supplies while I'm in the middle of a painting.
Here I just started laying down the washes that will eventually be built up to the watercolor painting, "Slender Man".