PPT Slide
Poor shadow shapes are another common mistake. Make sure your shadow shapes properly relate to the shape of your object. If you are not sure what the shadow shape for an object may look like, if feasible, try and locate the object you are trying to create a shadow for in "real life," and have a good look at it. Or find a practical sized replica of the object that you can study.
Place the object under a lamp and move it around to see how the shadow falls, or just take a walk outside and have a look at various shadow objects.
The next few figures show the same object, a car, with different types of shadows.