Start with a very broad PREMISE, being a teenager, working at a job, etc. It should be something that has a lot of SITUATIONS to draw from for inspiration. Choose something that you know about.
Come up with a THEME for a series of strips that is related to your PREMISE. The THEME should be smaller and more specific than the PREMISE. If your PREMISE is “being a teen”, a THEME could be “the first day of school”, “a sports season”, or “a hard class”.
Below is an example from “Bloom County”. The theme is “a snake in the swimming hole”.
Notice that each strip can stand alone and does not need the others to be funny. They are each a complete joke. However if you read them in order you get a story.
The first strip acts as the introduction. The next four are the body of the story. The last acts as a conclusion.
Choose a SITUATION for each 4-panel strip, keeping in mind that they are independent, but also work together.
When creating a 4-panel strip the following can help you organize your ideas. Remember it’s a joke not a humorous story. Lead the reader in one clear direction, then twist it at the end. Take them in a totally unexpected direction. That’s the joke.