There doesn't seem to be much of a resource on piano wrist techniques so I thought I'd share these with you. I use them in my own teaching and playing. It is important to have relaxed and flexible wrists when you play to avoid any unnecessary muscle tension which can, at an extreme level, lead to RSI. Plus it looks great!
This video demonstrates wrist movements SLOWLY and EXAGGERATED. As you get used to these movements, and particularly as you play faster, they should become smaller movements and less remarkable. But for the beginner who has never done these movements before, exaggerating them to begin with is a good way to learn it.