• You should have a good story.
• You should start with an easy comic character, like a stickman.
• You may want to make a sequel to your cartoon. If you make a cartoon, and plan to make a sequel, you may want to say 'To be continued in issue #2'.
• When a character is speaking, you may want to write what they are saying (or thinking) before you draw the speech bubble or thought cloud.
• Create text to go with your cartoon.

Also, try to create an emoticon: You can use this site Amused Smiley to help you, then animate the emoticon.

If you can't think of anything, use this tutorial to create a "Hole-in-one!"