This strategy is common among professional doubles tennis players like the Bryan Brothers. You often see points where both players end the point only a few feet away from the net.
If you can take over the net consistently in a doubles match, you will put pressure on your opponent. You can force them on their heels, and make them try to hit difficult low percentage shots. Volleys close to the net are usually easier shots as well, so you’ll win more points. You have better angles at the net, and you can smash the ball down into the court.
You should always be using this strategy at the net in doubles. Moving laterally at the net, especially when your opponent is about to hit a groundstroke, will put pressure on them. Tennis players are taught to not hit to the net player in doubles so they will likely try to change the direction of their shot, or hit a more difficult shot. This can cause countless unforced errors and frustrate the other team. If you are faking (see below) you may also get an easy volley to win the point.
It is much more difficult to hit a good volley from down low by your feet or ankles than a volley up high at your chest or shoulders. Hitting the ball at their feet puts the opponent at a big disadvantage. They will usually miss the shot or pop the ball up since they have to lift a difficult volley back up over the net. This is usually a good time for you or your partner to poach and put the ball away.
You can get the ball to their feet by hitting heavy topspin on your groundstrokes to get the ball to dip at the opponent’s feet. Another tactic is to hit a soft volley that stays low over the net before dropping to the opponent’s feet.
When you’re returning or hitting groundstrokes, try driving the ball deep in the court to push the opponent back. This will allow you to charge forward for the next shot. Typically the opponent hits a weak shot because you’ve forced them on their heels behind the baseline. This also gives you time to attack from the net. I like to do this with my forehand, aiming for the deep corner near the doubles alley.
One of my college tennis teammates used to say “down the middle solves the riddle.” This is a great doubles strategy, especially if both opponents are at the net. There are several advantages you get from attacking the middle of the court in doubles.
Almost every doubles player has a weaker backhand volley than forehand volley. If you can hit a hard, or low shot at the backhand volley of the weakest opponent, you will likely make them miss or get an easy next shot. When both players are at the net, this should be the default shot unless another obvious shot is better.