We started talking about 2 lines cut by a transversal this week in geometry. I had fun with the "magic hand" statement, and it seemed to work with my students. I held up my hand at the appropriate moment and asked them what it was ..... "a magic hand!", and then I placed it over the "4th line" that I had drawn.
I also mentioned that the two lines could be like sandwich slices and the transversal is the toothpick that goes through the sandwich. So when I had them identify types of angle pairs, I could keep saying, "who's the bread? who's the toothpick?". That seemed to help them be successful once the "magic hand" removed an extra line.