Here's a cover I recently did for Business week. It was a quicky, but I always enjoy this level of detail. It appeals to the neurotic side of me.
They needed a 60's flower power sticker that appeared to be stuck to the cover and was deteriorated. Sketches were going to be difficult for this particular project, so I started working on some illustrations based on their direction. I created 7 increasingly distressed versions of the flower for them to choose from. Then we went one step further and ripped off a couple big pieces.