I actually stole this idea from a Reddit thread years ago.

Part of my duties is training new, younger staff after they go through orientation. They are at my desk often looking at my monitors as I take them through the wonderful world of architectural drafting.

I have a series of folders on my desktop that can't be missed. I have an organizational system for them but thats not the point. The folder names however always raise some eyebrows. The tiny reactions I get makes training so much better.

Some examples of folder names are as follows.
"Ivory smuggling contacts", "architecture for interracial couples", "videos of Dougs exorcism", "farts" etcetera.

It has almost blown up in my face once, but still worth it for my own sanity.