agree with above. shadowboxing is all about painting mental scenarios and physically working them through. if I have an upcoming opponent I know fights a certain way, then I will be trying to do the thing necessary to combat their style. If I am adding an element to my own style is another thing, as in, say I want to work on my inside game, I imagine the invisible person across from me is fighting the style I expect most to use it.

Remember to try to fit all parts into shadowboxing, footwork, slipping, countering. And that bad (lazy) habits can be got there too, so use it wisely.