Pick a common thing and redesign it. Feel free to go as sci-fi or unreal as you like, or keep it realistic if you prefer. Come up with at least three significantly different designs and take one of them to the final, which should show several sketched views of the object and a full render in your style of choice. You may go further and come up with a brand, logo and title for your invention. Examples: cup, umbrella, teapot, saucer, car.
During the first session class, come up with at least three different things—fill up several sheets of paper with quick and rough designs.
As for the actual design, pick a direction and follow it in the way your approach the execution. For instance, if it's intended for stage, film or video game, the designs should look clean and simple. If it's for an illustration or a graphic novel, you can afford to be more expressive and loose.
If you feel enthusiastic, you can even make a 3D model of the thing, or the actual thing itself.
Format: any format.