My students have to give a number of speeches over the course of the semester. I always tell them they can use the same general topic for more than one speech, but each speech has to be different. Some catch on, others never fully understand the process.
If I give an example, some end up with a better understanding. One student gave a speech about one of the artist he considered to be the best rapper. Certainly this is a legitimate informative speech. Now for his demonstration speech, he can demonstrate how to write rap music or perform the art. For his persuasive speech, he can argue that everyone, even those who do not care for that style of music, should listen to it for thirty minutes, give it a try.
Students actually have all sorts of ways they can make things easier on them, but often times they just do not do it.
Teaching as an adjunct can be a lot of fun. It is also challenging. As I have encountered a number of situations, I realize such a blog can be helpful, both to me and to others.