pencil sketch 3 back of hand

This is practice to keep my eyes sharp so I can keep progressing, like lifting weights to strengthen the body. I have to make it simple enough to slip into my daily life. I might switch to pen as I don't seem to be erasing all that much. A sketchbook is nice because it has a stiff cardboard back and keeps all the sketches together in chronological order. However, any paper, even the back of an envelope will do.