This is actually a good question and it is important to get in to the habit of questioning and checking oneself. Here is how I answer this question.
- I don't need to get motivated for teaching. Teaching is a responsibility bestowed upon me as an academician. So I look at this from a responsibility perspective. I also have responsibilities as a parent, as a husband, or as a driver (if I am the designated driver), and for matters of responsibility, I don't need motivation. I know I should rise to the occasion.
- Teaching is my service to the students, who really need it. Today students have many alternatives. They can watch a lecture on YouTube, and can find a variety of study material on the Internet. But it is only I that stand in front of them in person and I get to serve as an example and inspiration to them. I take this role seriously and try to show the students how a curious researcher approaches problems and concepts. I try to show them, through diffusion, the love and fun of figuring out something new. At each class, I make sure that I take enough time to motivate my students about a question because this motivation determines the amount of attention my students will devote to learning that subject. (Yes there will inevitably be some students that look uninterested and doze off. With experience, I learned not to get demoralized by a couple such students, because that would be a disservice to the rest of the students who needs to see me motivated and engaging. I remind myself that I don't know the situation of the disengaged students---they may have other problems--, and I hope to be able to engage them at another time.)
- I regard teaching as a challenge and try to improve myself. I figured out early on that teaching is a good practice for giving better conference talks. When I was a fresh faculty, I felt very anxious and nervous before conference talks and before classes. But with practice gained via teaching this went away gradually, and I started to really enjoy teaching and giving conference talks. Nowadays I started to see teaching as a performance art. (Sure enough, I wasn't the first to think this, and there exists a book with this title.) When teaching, I look at the students' eyes and I try to connect. I try to see that they understand. I try to focus on the message that I want to communicate, and detach my ego out of the way. I had written on this at a previous post titled "How to present your work". Ironically if you put your effort in impressing the audience you will fail at it, but if you focus on teaching to your audience, you will impress them.
- I see teaching as an opportunity to simplify the material. When teaching I try to keep the message simple. I try to figure out the gist of the material, and challenge myself to communicate that to the students. This reductionist approach should be familiar. This is also how we do research. We try to reduce complex material by throwing away the accidental complexity and focus on the intrinsic complexity. We then attack intrinsic complexity to reduce it to simpler principles. Approached this way, teaching also serves a good practice for research. This type of practice helps for research in general and sometimes leads to a new paper in particular.
Some disclaimers are in order to put my advice in context. My teaching load as a professor in a research university is pretty light. I teach one class a semester. So, maybe some of what I say may look impractical for more heavy teaching duties. I teach mostly graduate courses, so advice number 4 about teaching helping research may be less applicable when teaching undergraduate courses.
Finally, here are some practical tricks I picked up about teaching:
- Prepare well. If I go underprepared to a class, I give a bland lecture, and I feel bad about it all day. Instead of wasting time feeling bad about bad teaching, I shift that time to preparing better for the class, so I enjoy teaching, and enjoy the rest of my day.
- Concentrate on a simpler message, and communicate that really well in several ways to leave no doubt of transmission. When I have a bad class, it is often because I tried to cram too many things and didn't distill my message to its essence. So I learned to leave out the unessential, and communicate the essentials as clearly and rigorously as possible. As you may have noticed, Powerpoint makes it easy to cram many things to lecture notes, so you have to actively resist the temptation.
- Slow down, pace yourself better. I learned to empathize with the students who are seeing the material for the first time, and need some time and immersion to wrap their brains around it.
- Ask questions to the class frequently. To get the students engaged, I direct questions to the class frequently, and wait patiently until I start hearing some answers or guesses. I comment on these replies, suggest alternatives, and ask more specific questions to direct my students to think harder to provide better answers. In order to learn the subject matter, the students should be forced to do some thinking.
- Use reenactments and use interactive material. To engage the students, I invite the students to the front of the class to reenact some algorithms by acting as the processes involved in the algorithm. I also don't shy away from showing YouTube videos that help communicate a point.