So, just one day after I learned of the existence of a specific term for these things, I got to witness the use of one in the wild.
My manager, for reasons that aren't terribly interesting, wrote "turning over a new leaf" on a whiteboard in the hall outside of his cube. One of my coworkers saw it and began making fun of him. "Oh, you're turning over a new leaf, are you? A new leaf? Why don't you learn English, ya flippin' idiot?"
At this point, pretty much all of us stuck our heads out of our cubes (not because of his tone, which is pretty much par for the course here, but to hear what he thought the phrase was).
Manager: Huh? What do you think the phrase is?"
Coworker: It's turning over a new lease. Jeez.
Pretty much everyone in the dept: Bwa-ha-ha-ha-ha!