Back in 2006, Tim Leong of Comic Foundry produced a great series of videos detailing my painting process on Mythos: Ghost Rider. Unfortunately, some of the audio is missing from one. I assure you, that is where I had the most intelligent things to say.
I don't paint exactly like this any more, but most of the process is the same. I tend to use more straight gouache these days, and usually begin with a monochromatic underpainting. Also, I paint at standard comic art size now (11" x 17" paper), which makes things a little easier on my eyes.
These videos cover the entire process and go into some depth, so I hope you enjoy them. Thanks again to Tim for putting it all together!