One of the reasons I like panels better than canvas is the starting over factor. It is much easier to sand down a panel than to just add more paint to a canvas. Once I started using panels, I never went back to the canvas. It is much more versatile for the type of work I lay down.
The other day I started on a piece for a friend of mine. Everything was well, and then I realized I hated what I was doing. So I grabbed the sander and went to town on the panel. As I was sanding, I started to see something I liked better as a beginning background. It just seemed to have a look I wanted for a soft pastel painting.
I made another video of the process. It is a little long and slow, but I do this for fun and not for enormous amounts of youtube popularity!