Cardboard or paper board in egg cartons replaces the plastic foam cartons. Paper wraps are being used by MacDonald's instead of the styrofoam cartons. Play Doh replaced clay. Paper clips, staples, pins, clamps can all be used to clip paper together. They will suggest pens, fountain pens, ball point pens, chalk, colored pencils, markers, paint, plaster, clay, soft bricks, etc.
C stands for combine.
List things that are combinations that are interesting. A pencil with an eraser. Broccoli and cauliflower to make the new vegetable. Sugar cookies with chocolate chips to make a chocolate chip cookies. Suggest food items, games, stereo and TV, etc.