There are a number of mistakes I have made teaching throughout the years, but I think perhaps the biggest was not providing enough studio demonstrations when I first started teaching art. Back then I had a fear that my demonstrations would not turn out well and I would lose credibility with the class if they observed my struggles. After a while, I understood that I was not giving my students the best teaching experience that I could. I would often try and verbally explain a technique or process and ended up wasting a bunch of time when I could have just simply demonstrated what I wanted my students to learn.
For a student, there is incredible value in observing someone performing a difficult task. Even if the demo does not turn out well, it is always a good learning experience. In fact, some of the best demonstrations I have given or observed involved a degree of struggle or working out that unveiled a deeper level to the process that most likely would not have been discussed otherwise.
The difference between a more successful demonstration and a less successful one can often be the result of both planning and outside forces. Some of the least successful demonstrations I have had were a result of being underprepared. I also typically have found more frequent shorter demos to be more effective with younger students rather than having them watch me draw or paint for an extended period of time. Keeping it simple also seems to work better than trying to cover more than one thing at once. If the process involves multiple steps, it is better to give multiple demonstrations rather than cramming it all into one day.
It is also important to keep the students engaged during the demonstration. Asking students questions while working or even giving the demo in the middle of the classroom often works better than being up at the front and having my back to the students. Lastly, having fun while working with the students, regardless of the results, is something that must not be forgotten. The best experiences I can remember as a student involved teachers who were willing to share their knowledge in a fun and approachable way.