Some of you may be curious as to how I apply the "Arched Fade" technique so I thought I would respond to that with a few examples. The top photo shows the same lifting action that I mentioned in my tutorial. Now take that same motion and follow the shape of your rounded object and it will help define the shape as well as indicate highlights.
A good thing to keep in mind is to always have your starting point furthest away from the light source and your lifting action should happen closest to where the light source is.
The Oscar Mayer Weinermobile, the iconic brand vehicle of the Oscar Mayer company, is a great exercise in lots of curved surfaces. Here you will see examples of the Push Fade, Pull Fade and Arched Fade techniques.
On any object that is curved, if possible, try to follow the contours of the surface to show the shape. On the shoes, I decided to use the "Flat Run" technique but instead of pulling straight lines, I curved them slightly to match the shape of the shoes.