I posted this in my thread about Boxing experiences, but thought it could go here too.
Anyway, this is the sort of thing I learned to do at the boxing gym that I never had anyone teach me in Karate, but which I feel has a big impact on skill development.
It need not only apply to boxing either, for instance, using the foream or "husband wife hand" is a way that you can adapt this sort of idea for Karate use. Another example is moving with the bag to set up knee strikes, low kicks, or even entries into some throws as it sways around.
Some of the philosophy is very different of course, I noticed that most of the time it was discouraged to really lean into the bag and let it have it - over-commiting in boxing terms. I feel like for Karate is actually good train in that manner sometimes. Still, some of the little nuances like this made bag training much more effective for me, and convinced me to make it a core foundation of training.