Decide whether you want to make your own foam props or purchase them. There are many dealers online that specialize in making custom foam props for stage productions. If you have sculpting abilities, you may want to purchase a variety of foam materials and foam cutting tools to make your own foam sculptures. While making your own sculptures might save you money, it's a time-consuming process reserved for someone with artistic skills.
Select Styrofoam for props that will represent a solid object, especially if actors will be touching the prop. Styrofoam is firmer and doesn't give. Cars, furniture, and statues are examples of props you would want made of Styrofoam. Styrofoam is also good for carving. It holds paint well, which allows for realistic textures and coloring.
Use foam rubber or some polyurethane foams for landscaping props that are associated with movement. Any prop representing something with a softer texture should be made from these types of foam. Foam rubber is also ideal for small props such as weapons.
Apply flat foam rubber backdrops for scenery. White foam rubber is easy to paint on and can be attached to a wood backing for sturdiness. Be sure the wood backing is on wheels to facilitate quicker set changes.