During winter vacation, I bought a new toy: I bought ... TEETH!
Now why, you might ask, did I buy teeth? Well, the reason is so that I could teach pronunciation. By showing students an accurate dental cast of the mouth, I can talk a little about the parts of the mouth: like, for example, where the alveolar ridge really is! In the past, when trying to show pronunciation to students, I've used my own mouth as an example. For showing TH, that's pretty good, but L and R are a little harder to get across because it's difficult for students to see into my mouth to see what's really going on there, and I'm a little self-conscious about doing it. Like, for example, I often think: did I brush?
The model teeth are perfect because they're always clean and never smell (at least not like anything except plastic), and I can open it wide and take it apart, and better demonstrate where the sounds of English pronunciation come from.
I'm hoping this will be more useful next year.