In making the Monarch Theatre documentary, Your Cinema Needs You, there were obviously a lot of random things that I found that didn't make the final cut. There were also some entertaining cross promotions that unsurprisingly went out of fashion relatively quickly.
One such promotion that I found particularly funny was this one from 1957.
A local dry-cleaner was advertising the re-release of Disney's Cinderella and asked children to wear their "costume bags" to the cinema - essentially encouraging children to put dry-cleaner's bags over their heads to dress-up for the show. Shockingly, I couldn't find any examples of this "costume bag" promo ever running again, but just imagine how funny it would've been to see that theatre full of saran-wrapped children.