One of the best teaching aids of the last couple of years is smart phone video technology. In my smart phone and Ipad I have the V1 a swing analysis software app. It not only allows me to show my pupils their swing in slow-motion & frame-by-frame but I can also make side by side comparisons, use multi-colour drawing tools and send it to them via email directly from the practice ground even before the lesson has finished! Simply unbelievable!
After having tried several apps I currently use the V1 app which I believe to be the best on the market. If however you know of any other app that is better please let me know.
Side by side comparisons
Multi-colour drawing tools