I'm not used to the angles that balls come at from and especially when I'm close to the net like I'm almost never in singles
I like to keep this a virtual community only, but happy to offer tips online. Even if it doesn’t help you, maybe it will give some food for thought for others. When I’m at the net, I focus on three things.
1. I first focus on the opposing net player to see if he is reacting as if he will intercept the ball hit by my partner. If so, I have to be alert to react to the net player‘s shot with my racquet up and it will have to be an instinctive response. But I might take a step to the middle after split-stepping if my partner‘s ball is somewhat low and not an easy put away for the opponent.
2. If my partner’s ball passes the opposing net guy, then I observe the quality and direction of my partner’s ball as it crosses the net and gets into my field of view. If it is a high caliber shot that is deep, wide, heavy and/or low where the opponent is going to struggle to hit a quality shot, I will take a step forward after split-stepping - this is very important to not be caught flat-footed at the net and gives me a chance to poach. If my partner’s shot is weak in any way (slow, mistimed, suicide depth etc.), then I split-step and take a step back so that I can react better to a lob or a hard shot hit at me or at my alley. The same applies for my partner’s serves - step forward on good/average serves, step back on very weak serves
3. Just when the opponent is about to hit his shot, I will move laterally also following the direction of my partner’s shot - wide if wide and to the middle if to the middle or to the opposing net player‘s side/alley. I won’t move early laterally as it gives the opponent time to change his shot easily. There are exceptions like when my partner hits a great shot wide and here I might move to the middle to get a likely poach and take the risk of being passed DTL with the bet that the opponent will likely miss if he tries to change the angle of a great shot.
If both opponents are at the net along with you, the gap between the front/back step and lateral step is almost zero and you move more diagonally rather than taking two steps separately as you don’t have much time to react. In all cases, feet have to be active on toes, body weight has to be forward and racquet has to be up in volley alert stance with both hands gripping the racquet (offhand on throat) allowing me to turn sideways quickly to either wing or do a reflex volley if hit at me. If you follow this 3-step approach, then you might time net shots better.
Key for a net player is to have the attitude that every ball is his when moving his feet, but actually hit only the volleys where he can hit an advantageous shot. When you move forward, you can typically hit an advantageous volley, but if you can move only laterally to hit a low volley, you won’t get much on it and better to let it go. Similarly let go the volleys you have to hit on the stretch down the middle if close to or below net level as your partner might be able to deal with it better. Most of my aggressive volleys at the net are done with feet/body moving forward quickly so that I typically make contact within 2-3 feet of the net - the better my partner is, the more it happens. I make volleys 10-15 feet from the net only when I am approaching after a serve, return or good baseline shot.
Also, you might want to use poach/stay signals a lot and do mostly intentional signaled poaches until you get your net footwork timing right. Here the trick is to play closer to the middle and go for the poach as late as possible as part of the net player’s job is to clog up the middle especially when your partner is serving. We even call poaches on Return + 1 shots to keep the serving team guessing especially if the server stays back. The more athletic you are, the closer you can play to the middle at the net and adjust to move to one side late. Also the optimal distance to stand from the net varies depending on the level and how athletic you are. All the best in singles and doubles!