When I was young, one way I would practice drawing was by finding a particularly cool splash page from one of my favorite comic books, and I would draw it free-hand.  This exercise taught me the necessary skills it takes to draw; patience, precision, and vision.  I was a bit of a perfectionist early on which slowed me down a bit and in doing so I learned that having fun with art is just as important as making something look cool.  I also learned that I could draw something just as good as a Todd McFarlane if I was patient and practiced enough.  I haven’t stopped drawing since.