This is my first post here, but I've been lurking around for a while, reading the threads that interest me. I felt this was the first thread I could contribute anything useful to. Anywho... The only time I ever force myself to kiai is when they are in a kata I am practicing, I find that if you throw a attack with enough "commitment" for lack of a better word they come out naturally. We were practicing some kicks against a padded "shield" another student was holding, every time I did a kiai I would manage to push that person off a few steps, if I didn't they just sorta stood there. I didn't force the kiai, it just seemed to follow the intent of the strike.