A good footwork is essential for playing good tennis. Good footwork means: small steps, ability to change direction swiftly and to always be on balance while performing sprints sideways or forward and backward. Unfortunately, most tennis players don’t give enough attention to footwork. They might go for a run, but long distance running won’t improve the foot work.
Good footwork drills should imitate the movements on the court: short sprints and changes of direction. Footwork drills should focus on speed, strength, explosiveness and endurance. It is extremely important to practice your footwork regularly so it would become second nature to you, and you would never need to think about it in your matches.
When you know what you want, and you want it bad enough, you will find a way to get it.