DIY Coral Reef prop/party décor! Things you'll need: Large cardboard/wood surface - lined with wax paper Wood dowels Can of spray foam Spray paint What you do: Place wood dowel on wax paper and secure with tape. Use spray foam to create organic free flowing motions that resemble coral. Note: Foam will expand so don't spray too much in one area. Let dry overnight. Carefully peel off wax paper. Then spray paint.