When you are approaching the net or you are already at the net, always assume the next shot coming to you will be a backhand. Your ready position should slightly favor a backhand. Most intermediate players hold their racket straight ahead of them. If you correct your ready position to slightly favor the backhand, then the typically weaker volley - the backhand - will have better preparation. The forehand volley, typically over powered, will have less time to pull back too far, thus gaining more control.
When all players are at the net, the volleys are fast and hard, and favoring a backhand will give you a better advantage to block balls hit at your body. You will be able to maneuver the racket better
for volleys and will hit more volleys with the backhand in this situation.
After you hit an overhead, assume the next shot will be a backhand volley. After you hit a forehand volley, assume the next shot will be a backhand volley. Even after you hit a half volley, assume the next shot will be a backhand volley. This will correct the usual inequity of over hitting the forehand volley. In addition, when you are being attacked at the net you will feel safer and will get hit a lot less by the ball.
See you on the courts!