I save cereal boxes because they are about the right thickness to use for sheet metal work. I use them for patterns to make sheet metal parts.
I had a thought the other day to build a template for a transmission hump. I covered the hole over my TKO with cardboard, used a 3" lid to get the diameter of the shifter plate.
I screwed the cardboard to the hole, covered it with wax paper, and then began the fiberglass layup process.
Fits like OJ's gloves