I covered the cardboard with aluminum foil. I cut wiffle balls and round styrofoam balls in half and then hot glued them to the cardboard base, these will represent bubbles in the cauldron. (I would recommend using all wiffle balls of various sizes and eliminate the styrofoam balls.) I used orange christmas style lights and then attached them to the board and tucked them into holes of the balls. I attached them with 2" boxing tape, you may want to attach them with something else. I have one set of lights set to flash and one set to stay on constantly. It is important to put in the flashing light bulb before the next step.