If groundstrokes have evolved and moved to the forefront of the modern game, especially at the higher levels, then volleys have been the component retreating to the background. It's not that the skill is no longer important or worth developing; approaching the net is still an effective tactic and core ingredient for successful tennis.
But given the prevalence of aggressive baseline play, it has become increasingly difficult for players to find opportunities to transition forward. However, a player can make volleying a trusted asset using an assortment of approaches, along with gaining a better understanding of when to attack.
Once the ready position and grip are established, the rest of the volley sequence falls into three main parts: advancement, preparation and impact. As with any stroke, each segment connects to the next. The proper execution of one makes the subsequent part that much easier and more effective.
Players move forward after they have identified—and decided to exploit—a vulnerable opponent. Developing the desire to take advantage of these situations is a prerequisite to mastering this part of the volley sequence.
By advancing forward, the player profits from simple geometry: The closer the player is to the net, the more angles there are available, and the better the player's chances of hitting an effective volley. The advance forward could be a result of offense, defense or a miscue such as an opponent hitting a poor shot that lands short in the court.