While out on a date night my wife began sketching an arm with a hand on a napkin. As she drew the sketch was turning out cute and cartoony. She asked me to give her a lesson based on her sketch. The first thing I thought about was the shapes must taper! I started sketching the same drawing she did and began tapering the shapes of the caricatured anatomy. I also added in straights against curves but the tapering shapes were what I wanted her to grasp right off the bat. I started speaking the direction of "start with a shoulder, it's a bit round then down to the biceps, down to the elbow...etc" The skin closet to the the joints such as the elbow, wrist, and ankle are some examples where the shapes taper in. the rest of the anatomy could very in almost any kind of shape depending on the person. My wife was catching onto the lesson and started asking for more tips but suddenly my buffalo chicken sandwich arrived and art school ended. Tapering shapes will help any drawing or sketch. This is deceptively simple but a good one to remember. It's enemy is symmetrical shapes and parallel lines. Lastly I thought this simple idea would help.