i found duck walk really useful for not only leg strength but also the ability to keep your waist/chest/breath relaxed while training.
probably best to check your form and make sure the knees aren't misaligned too much
i would also definitely recommend mindfulness when doing any iron palm/fist stuff, incl rice punching (sort of like prana said)
I always do that before and after iron palm and it helps me ( i always use linament too)...but i can't speak for everyone
__________________________________________________ __________ "I'm just trying to lull you into a genuine sense of security!"