Still working on learning to design graphics in Illustrator using the tracing technique. Will not presume to write a tutorial on how to do this. Just not skilled enough to be telling anyone how to trace with Illustrator. You can find countless tutorials on the web. The one used as a basic guide for tracing the Chanel sunglasses used for this object can be found here
We grabbed an image of a pair of Chanel sunglasses from Google images and followed Steps 1 and 2 to set it up for tracing. After that it was pretty much trial and error.
Tip: You can try using Effect->Stylize->Rounded Corners to soften the edges of your shapes; but keep in mind that this will not work for all scenarios. It works best for shapes that do not have 4 distinct corners. Feel free to share if you know a more effective way of softening edges in Illustrator.
Self grade: D+