It depends on what I'm trying to break. For bricks, it would be the downward palm strike. For boards, I prefer hand strikes for 1 to 3 boards and foot strikes for 3 or more boards because of the power (it's not a typo - 3 boards can go either way for me). I like to use the spinning side kick to generate more power but the more boards you do the more precise your technique has to be. Thanks for the post, Brewer. I will throw a topic about this on the Body Mechanics forum for discussion as well.