Obtain three equal-sized pieces of Styrofoam sheets. Use the original size from the store, or cut three equal pieces down to size with a utility knife, based on your room divider needs.
Decorate each Styrofoam sheet panel in the method of your choice. Attach pieces of fabric to the sheets with a solvent-free glue to give the divider some texture. Or paint them with two layers of latex primer, and cover them with oil paint to prevent the Styrofoam from deteriorating.
Line two of the Styrofoam panels up on a flat surface, with the bottoms as even as possible. Leave a gap of about 2 centimeters between the two.
Place a set of hinges in the center between the two panels. Poke the screws through the screw holes in the hinges into the Styrofoam. Remove the screws, fill the holes with metal epoxy and re-insert the screws into the holes. Repeat this process with a hinge along the top and along the bottom. Allow the epoxy to set overnight.
Turn the two attached panels over. Line up the third panel, and repeat the installation process with the hinges.
Stand the Styrofoam room divider upright, and position it by bending the hinges in place so it stands freely on the floor.