A diorama is a three-dimensional scene created inside a shoebox or similar container. To make a desert diorama, research desert landscapes, people, plants and wildlife. There are several types of deserts, so choose one and keep your scene accurate to that particular ecosystem. Make it even more interesting by creating a scene that tells a story for the viewer.
There are multiple types of deserts on Earth, each with its own climate, geography and wildlife. Some deserts are characterized by rolling seas of sand, while others are famous for cacti and others still are cold and covered with snow in the winter. Learn more about different desert environments at the University of California Museum of Paleontology's website.
Diorama backgrounds can range from very simple to quite complex. Consider how much time you have to spend on your project to determine how basic or detailed to make the background. It could consist of just colored construction paper to represent water, sky, earth, etc. You can also paint a background or color one with markers or crayons. For a high level of detail without investing as much time, try cutting photos of desert landscapes out of a magazine and gluing them into the box. Your background should cover every surface of the inside of the box.
Make your diorama three-dimensional by adding elements to the inside of the box. Plants and animals cut from paper can be attached to the walls, floor, ceiling and back of the box. Try hanging elements from the top of the box. Papier-mache, clay, styrofoam and cardboard all make useful materials for fashioning sand dunes, people, animals and other structures.
To add some fun texture to your diorama, dilute some white craft glue with water and paint it onto the floor of the diorama. Sprinkle sand over it to make a real sand floor. This looks particularly good if you have used styrofoam or papier-mache to build up sand dunes.