Here's a fun drawing exercise that's great to have under your hat (or up you sleeve) when the kids are in need of an activity, and you're in need of an activity that doesn't require fancy supplies or make a mess! I saw this idea a while back on Craft Schooling Sunday (will provide the link when I have a spare moment to look for it) and finally got around to trying it out! I drew the pink version and my daughter did the versions below.
Trace your hand on a piece of paper. Draw lines across the paper, and when you reach the outline of the hand, make a curved line the spans the area within the hand. Continue in the same manner until the whole hand is filled! As you can see in my example, the fingers were the most successful part of the drawing as the lines were the most curved. Enjoy!