Sign up for hip-hop classes to learn basic moves if not already dancing hip-hop. Footwork is an expression of hip-hop, and many of the core moves are central to the hip-hop genre. If you don't already know the basics of hip-hop, pop and lock, slides and other moves, then classes give you the basic structure of routines, knowledge of the style and music.
Practice these basics in double, triple and even quadruple time. Footwork dance is fast-paced. Once you can solidly do a move on the beat, try doing it at double time. Don't go any faster until you've mastered that speed, and then step it up again.
Add some facial expression. Footwork is a very expressive dance, facially. So be sure to get your whole face involved.
Cut in some breakdance tricks. Remember that the footwork dance style is an outgrowth of b-boy dance, and many of the quick bounces and inversions play nicely into the fast-paced footwork style.
Keep the footwork routine clean. Footwork dances are distinct from its Chicago counterpart of juking, which is a more sexually suggestive dance.
Add level changes but stay on your feet. You don't need to stay upright the entire time, but footworking rarely sees dancers completely off their feet.