I always receive some very bad sidekicks when I try to go offensively while in kickboxing. Mainly because I try to make a jab with my right hand but the kick comes too fast (or I'm too slow) I have countered this a bit by putting my left hand on the side while making the jab to protect myself. It is sometimes effective but lowers my defense on the left side of my face.
So I want to address the problem at its root: footwork and speed. I will not ask which is the most effective way of improving those because it is too subjective. I am asking about an effective way to improve it and that is easily accessible (i.e. no need of special facilities or equipment)
For instance I have heard that to improve footwork, dancing is effective.