These two guides can be very useful when it comes to shading. The shadow placement isn’t necessarily the problem, but rather the method used makes the shadows seem muddy in places. Also make sure you’re shading by using a non-black color on a multiply layer. There’s many ways to pick your shading color and the guides cover that a bit. The biggest thing is making the shadows look sharper, even if there is some softening at the edges.
Well when you report an image with a updated one. It will remove the old pic and description with the new one while merging the old comments with the new comments.