Peter Bagge, Gilbert Hernandez, and myself are doing a "cover-swap" on our new Dark Horse series coming out in the Spring - so there will be a "variant" cover for each series. Gilbert did my cover and I got to do Peter's.
I usually end up throwing away most of the process stuff and keeping the final product only but got too busy to clean my desktop so actually saved all of the steps accidentally!
Here's the process -- 1. Thumbnails: I gave Peter 3 to choose from - the last one being a sort of Conan-esque cover which is the one he liked best.
2. Pencils: I scan this in so I can see how the logo/type will look over the top of it and for editorial approval.
3. Ink/color: This is the raw image - the original art. I try to do as much at this stage as I can so I don't have to spend a lot of time on the computer.
4. Photoshop/design/logo: I stick the logo on and adjust the color, etc. depending on what the piece is and how it looks with the logo colors. In this case, the background was way too light so I darkened that up and also had to fix the skin of the girl kneeling down (she's not white).