I have started this year making the occasional video for my classes. The material for the videos has not been anything new for my students up to this point; instead, I use videos as a way of refining and recording lectures so that my students can refer back to them for review or if they were absent and missed the original. I could see myself in the future, after more time creating videos, implementing something of a flipped classroom model, but for now the opportunity for review or makeup seems to be appreciated by my students.
I use already-made PowerPoints combined with iMovie to make my videos. It is also possible, and quicker/simpler, to use some kind of screen capture program, such as QuickTime. I have it in mind to do a series on this blog, geared specifically to teachers, about both techniques.