The ideal is to draw from life, but I find it really anoying, because I am very shy and hate people looking at me, and I am even afraid that they get upset or something because I am drawing them. So, to keep practising fast drawings, I use Posemaniacs, a really great page to train the right side of your brain. However, I will keep on trying to draw from life, because animation is life and the only way to learn it is to observe real people, animals and whatever.
So, here are some thirty-second drawings, done this last two days. They are suppose to help! Next to them, The Animator's Survival Kit, one of the greatest books about animation.