Yeah i was going to suggest basketball to Sharla, but i guess you already new that!

I think footwork is down to 3 real things, balance, expierience and memory.

For balance try one of thoe flattened balls. Place both feet on and practice balance. (same idea as a wobbleboard i hear but iv neverr used those.)

Expieience will come from sparring and shadowboxing, more so sparring as you move as demanded.

After that, in fights good and correct footwork seems to come naturally as your brain automatically seems to employ the calculated movements you practised earlier...
For me it shows the depth of the brains power as if you watch yourself on tape after you say "God i was moving well." But the thing is you only decided which way to move, ur brain and body moved in the manner you practised, it's strange.