An anaolgy is any comparison between two things. The first step to finding a unqiue analogy is to think about things that you are really familiar with. In order to make a comparision you have to know a lot about both things, not just the cellular organelles, but also the item(s) in your analogy.
Some possible examples include comparing the cell to your school, your home, an amusement park, or even your favorite restaurant.
Think about the key parts of the cell and what they do.
Nucleus: control center
mitochondria: powerhouse (energy)
lysosome: garbage disposal of the cell
Lets say you are going to compare it to your home. Who runs your house? One of your parents is probably the nucleus of the house. Who supplies all of the energy? Maybe you think of energy as food, so who cooks the food. Maybe you think of energy as excitement and fun, so who is the most energetic personality in your house (maybe a sibling or a pet).
I hope you get the point. Anything can be an analogy, just think about a situation that you are familiar with. The point of this assignment is to help you remember what each organelle does, so the more creative you get with it, the better you will remember the functions come test time.