I came across this video some time ago and ever since then it's how I've folded all our shirts. It works a lot better on men's shirts than on women's, which are more curvy.
The video is in Chinese, but it is easy to follow, I didn't understand what he was saying either (my Chinese is incredibly limited). It really is very easy and it's second nature to me now. It has also cut my laundry folding time in half!