None of the writeups above has explained where
clichés come from.
Clichés date back to the early days of movable type. It was found useful to keep well-used phrases set in type in order to save time when printing newspapers. These were kept as blocks ( cliché is French for 'engraved block') and used so often that the more modern use of the word became attached to them.
According to a recent discussion on alt.books.pratchett the first cliché recorded was 'described as a respectable married woman', and the author Terry Pratchett says that as late as the 1960s trays of clichés were kept at the local paper where he worked for use as headlines.