A few people have asked about my digital painting process, so I put together this GIF of my Jeff Leppard painting in various states of completeness.
I paint mostly in Photoshop, though I often sketch in Sketchbook Pro. Here's a brief description of the steps I went through.
1. Rough line-work using a pencil brush in Photoshop. The brush I like is included in this pack by Ray Frenden, along with some other really nice brushes.
2. Refined line-work using a thicker brush.
3. Adding values. I block in the shape of the figure with a standard hard round brush, then set the layer to 'lock transparent pixels', which allows me to render the shadows and highlights of the figure with a soft airbrush. The arrow is just to help me visualize where my light source is.
4. Blocking in color using a soft airbrush on a new layer set to 'overlay'.
5. I cleaned up the edges of my linework, then masked and colored it to blend it in by color-picking local colors (If anyone is interested I can go into more detail on how I do this step.)
6. I add some adjustment layers to increase the saturation and alter the color balance a little, then I start painting in small details and some strong shadows to improve the depth using a hard round brush.
7. Added in a background and some smoke from the RPG. You can see the beginnings of the text at the bottom. At this stage I opened up Illustrator to work on the custom text.
8. The finished piece. I added some more adjustment layers (quite a few actually), as well as a paper texture to give it that fold-out poster look. Also added a handmade lens flare, because try as you might to deny it, lens flares are just cool.
Hope that helps. Let me know if you have any questions.