Revolutionary drawing book, Drawing On the Right Side of the Brain, by Dr. Betty Edwards has been a staple for my classroom for years. Here are some students just starting on the path towards mastery of observational drawing through the use of Pure Contour. In a pure contour drawing, you draw just the edges of the object ( in this case our hands.). To further complicate things, they are not allowed to look their papers! This allows them to completely focus on getting the hand to follow what the eye sees. Challenging, but rewarding. Find good examples and some of her exercises on her website, http://drawright.com/ .
We then moved on to drawing objects with a modified version, where they are allowed to glance at the paper. Starting to get some great results.