I've been teaching this class for about a month with another teacher, but this is the first time I had a "free hand" and she just sat down like a student. The topic was radio and TV, and first I pretended it was a TV-show. I walked around with the blackboard eraser as a microphone, interviewing students about their favourite TV-programmes, the benefits of TV over radio and vice-versa. After a while I had a list of different program categories on the blackboard (sports, national news, international news and so on).
I then explained to the students the concept of improvisation, and asked who likes watching the news. The (poor?) student who raised his hand was given my improvised microphone and told to make a news broadcast. I provided the sound effect and intro jingle.
I was rather nervous as to how this would go, since they always prepare carefully before performing a dialogue for the other teachers, and their English level is not always great, but the student rose to the challenge! And so, with different students, we had fascinating but rather short broadcasts of international and national news, sports (featuring me as a javelin thrower with a broom in slow-motion as the excited sports journalist, aka student who had almost never spoken before the class before, described my gracious moves), and game show (with host and two contestants who had to answer questions in order to gain the prize). We also had educational TV about the use of computers in Chinese classrooms (I never supplied the topics, the students invented them off the top of their heads, except for the game show and sports), but looking back I see that I forgot the weather.
In the second class, I woke up that half of the students that had clearly been sleeping during recess with a bit of Simon says (problem is, I'm no good at hosting Simon says, since I always get so dizzy from all the jumping and head wiggling and so on, that I give up before half of the students are out. Then we did the 20 questions that were described here earlier. In the end we sang Happy birthday to a student which had her birthday today.
All in all, it was very much fun, the students responded wonderfully, it was very much improvised from my side, and I walked the thin line of making fun of myself and them (so far they think I'm hilarious, but I'm afraid someday they'll call my bluff and see that I'm just a pathetic guy a few years older than them, with no prior experience, trying to teach a university class. If every day was like this, I wouldn't need pay to do this job.