Thanks Michael and Daniel. Sketch looks good by the way Daniel...I wouldn't say it looks overworked, you might even try being more aggressive with your shading and highlights, just make sure everything is purposeful (i.e. the airbrush bleeding onto the top of the midsole doesn't make much sense and is flattening the sketch)
'...a root word of technology, techne, originally meant "art." The ancient Greeks never separated art from manufacture in their minds, and so never developed separate words for them.'