For me, footwork has to do with always moving your feet. If you find yourself running to the ball, planting your feet, and waiting for the ball to come to you, then you're likely doing something wrong.
You should be making small steps, small movements to better put yourself in a position to hit the ball. Don't plant yourself down and make adjustments by how far away or close to your body you swing the racquet. Get your body to the ball where it belongs and swing normally.