I liked drawing perpetual things.
For example - a running horse, or a rolling soccer ball.
I would make 2 iterations and repeat them over and over.
It is also easy to print these stuff if you are ready to spend a dollar. Then from 2 seconds of running horse, one could make a minute of animation.
Yup I know what you mean, like the backgrounds in the old cartoons where they drew a building and a cactus in the background then 'looped' the animation to show the character running away from something and you would see the same cactus every two or three seconds.
Thanks for the comment!