Create your cartoon characters by taking ordinary people and exaggerating their individual characteristics. You can do this by enlarging certain key expressive features such as the head, eyes, nose, mouth and hands. You can also make the characters have smaller bodies in proportion to their heads, hands and feet.
Animals can be used as cartoon characters as well. You can make anthropomorphic animals, which means giving these creatures human characteristics. The easiest way to do that is to make animals walk on two legs and give them mouths that can talk. If you want to take it to the extreme try dressing you cartoon animals in human clothes. This works best if you can come up with a theme for their clothing that matches a stereotype about the animal. For instance, a pig could be wearing sloppy country bumpkin clothes, you could dress a rabbit up as a hippie or make a frog into a French poet with a beret.
You can create motion with your cartoon drawing if you want to turn it into animation. To do this one of the best ways is to start with a basic figure and add motion by layering sheets on top of the figure. On each of these sheet the drawing should be altered slightly to create the illusion of movement. For example, to show a cartoon character running, you would start with a character standing, then in the next illustration show one leg slightly bent. From that point you would show the next illustration with the character's leg bending further until the character looks like he or she is breaking into a stride. Then you would draw the other leg slowly moving forward and bending as the first leg moves back. Repeat this process for as long as you want the motion to take place.
You don't have to animate your cartoons to create a sense of motion. You can create motion in a cartoon strip by showing a character in one pose in the frist panel and then changing the pose completely in the next panel. The reader's mind will fill in the gaps and imagine that the character has moved to get into that new pose.
You can create humor by placing your cartoon characters into situations that make them uncomfortable or are impractical given the nature of your character. For instance, if you have created a cartoon beaver that is also an idiot, try placing him in charge of a large bank. The difficulty of running a bank would create enough conflict for a normal storyline but by having an absent and simple-minded beaver in charge of the bank, you have created comic tension.
You can also use observations that you have made about little details in life that seem absurd as launching points for your cartoons. These can range from the truly mundane such as grocery store etiquette to outlandish prices on medical bills. Use the personality of the characters you have created to comment on these day to day experiences.