Well, as a firm believer in my heavy bag but also as someone who's arms and wrists are critical for my work I've found myself increasingly working on my palm strikes. Since strikes for me aren't generally primary I do still want to be able to do some damage without destroying my hands/wrists. And for me that means practicing on a heavy bag to make sure I know what I'm doing and can deliver it with power and accuracy. So palm strikes to the floating ribs, liver strikes, as well as some head shots can be powerful weapons to have. And I don't worry so much about developing skin of leather and knurled knuckles some of my friends have from too much striking. I've known older guys whose hands were crippled from too many years of makiwara or even heavy bag work.