In printing, a cliché was a printing plate cast from movable type. This is also called a stereotype. When letters were set one at a time, it made sense to cast a phrase used repeatedly as a single slug of metal. “Cliché” came to mean such a ready-made phrase. The French word “cliché” comes from the sound made when the matrix is dropped into molten metal to make a printing plate.
His secret weapon on how to use clichés:
The effective way to use a cliché is to point to it and then do precisely the opposite. Juxtapose the cliché with the unexpected truth of what you have to offer. …. I often use the Encyclopedia of Clichés to find clichés that then inspire opposites.