After the sketch comes the rough pencils. I used to pencil much tighter than this but I found that if I keep the pencils loose, it gives me more room to explore when I drop the color flats on top of the pencils. This helps give the work a sense of life in every stage - which is very important to me.
You'll also notice at this point I chose to really zoom in on the figures. I love the atmosphere of the pulled back view in the concept sketch, but football is about action and clashing warriors. An up close shot, with the same color treatments carried through, would accomplish exactly what I needed it to.