The answer to this question is really simple for some animators and that is they take inspiration from themselves.
Believe it or not, many artists keep a mirror by their side while creating some of the funniest cartoons of the world.
Scroll down to have a look at these epic moments!
Image Courtesy- izismile.com
So..If you want to experiment with your cartooning skills..go ahead, look yourself in mirror and make weird faces ;-)