Lay a shoebox on a work surface with long side down and the opening facing toward you. This is how you will display the circus scene.
Find a picture in a magazine of people in a stadium. Cut it out with scissors. Another option is to print out a picture from an online source or draw and color one yourself. The picture needs to cover the entire bottom of the shoebox in order to provide the circus background.
Glue the picture to the background inside of the shoebox--the actual bottom when the opening is facing up. The side of the shoebox that is laying on the work surface is the floor area of the diorama.
Cut green felt to the size of the floor of the diorama--the section that is laying on the work surface.
Attach the green felt to the floor with the glue.
Cut out a strip of white paper that is about 3 inches wide and as long as the bottom of the shoebox. Use crayons to draw a railing on the strip of paper.
Tape the strip of paper across the floor of the diorama so it stands up--about 1 inch from the audience picture. This gives the circus diorama depth and acts as the railing to separate the audience from the wild animals and circus performers.
Cut a length of black yarn that is long enough to touch both sides of the shoebox across its width. Tape it to either side to form a tightrope for the high wire act.
Glue a large rubber band to the floor of the diorama so it lies in a circle with the edges standing up. This creates the ring where the animals demonstrate their skills.
Set a miniature toy elephant, an amusingly dressed dog, a lion or a monkey in the center of the rubber band ring. Glue it in place.
Place a miniature plastic figure that resembles a circus trainer outside the rubber band ring circle and glue it in place. Tape or glue a toothpick in its hand, if possible, to represent the training tool used to instruct the animals.
Stand a plastic figurine of a clown in one corner of the shoebox so it looks as if he is watching the circus act.
Wrap some plastic wrap over the opening of the screw lid from a bottle of mouthwash. Glue it on the floor near the clown. This represents a bucket of water clowns often use to drench people in the stands.