Apply superglue to each corner and in the center of the container. Place a blue segment of blue felt material in the bottom of container. Smooth out to flatten any wrinkles in the material and allow to dry. Use scissors or a utility knife to cut the Styrofoam ball in half. Discard one of the Styrofoam pieces.
Place the remaining Styrofoam piece on a flat, sturdy surface. Mold green clay around the rounded portion of the Styrofoam piece, leaving the flat side uncovered with clay.
Use hands to mold and shape the clay into an island. Add small hills or mountains, if desired. Gently pick up the clay and Styrofoam. Use one hand to hold it upside down. Add glue to the rim of the Styrofoam piece. Carefully place this into the center of the container. Add small plastic trees, if desired. Allow glue to dry before moving.