I sometimes do teaching that's more like a shop class than math. And there comes a time when you have told a student "you need to use masking tape to hold the pieces of your project in place before hot-gluing it, otherwise your joins won't be aligned." as many times as you can . The time has come to simply watch as they try to hot glue it while balancing it with their hands.

"The last piece won't fit!"
"How do you think you could avoid this problem?"

IDK why I'm thinking of this now.