Steampunk Veronika

Cover to my art book, "Steampunk Rising: The Art of Sandra Chang-Adair", published by SQP Books.
I was tasked with creating a cover for my book and I looked at Heavy Metal Magazine covers as reference. I knew I wanted base the likeness of the girl on playboy lingerie model Veronika Kotlajic for the cover. My first concept of the pencils looked more like a Las Vegas showgirl riding a dinosaur like creature and she didn't look like a warrior. On the second attempt, I completely erased everything and made her costume more steampunk. I honestly can't remember what I originally intended her to be sitting on. On the third sitting, her costume started coming together and putting down the background tone helped cement the color scheme later. I decided that she should be sitting on a tank and I researched the web and found some good reference for a WWI tank.
A lot of the time, I have a vague idea of what I want to paint and the art slowly metamorphoses into being. I think this prevents my work from getting too stiff, but usually the client requires pencils or comps from the onset.