Being a bit slower in getting to the net, this usually translates into my having to hit a half volley. The fact that I have confidence in my half volleys allows me to be a bit more intrepid as I lumber toward the net. Clearly, good foot speed and proper footwork will help a player to close the net more effectively. I regularly run 25-yard sprints to improve my forward motion foot speed. In fact, I believe sprints are much more useful than distance running for tennis players.
Proper footwork is a little more difficult.
Professional players on both tours use the split step when serving and volleying. This enables the player to move in any direction that the opponent's reply may go. Most recreational players do not need to develop the split step to be successful at serving and volleying. Usually, this is sufficient to allow movement in any direction. However, if you want to excel at the serve and volley game, you need the split step.