What a slide C4ill, your explanations were really good and I wouldn't have said any better even for my side I'm supposed to know perfectly. And to discover the end of the point was really funny

If you want to improve your moving, remember what the goal is in very simple terms :
1 : Moving as fast as possible to the ball
2 : Get the perfect position to hit the ball
3 : Charge your shot as much as possible
Try with some practice sets to only concentrate on those points, anf first of all to
never go to the wrong side enough so you wont mistake anymore. That allows you to simplify the problem : is the ball going right or left ? (for the moment getting a dropshot is the least of your problems). You'll think later how to position yourself closer or farther to the baseline, first of all you need to get to the ball naturally without hesitation. And for that, your mind is what matters the most.
To me, you start to get to an interesting level when you are able to see things a very simple way after studying and understanding all the mechanics and the tools you have and master them properly.
This guides me to something that is super important as a step to see a real improvement in your game : know what to expect. Understand enough that it becomes natural at a point what your opponent can do in every situation. Because in a way this is like a fighting game : each one as 2 different characters with their qualities and defaults and you're fighting each other according to what the other do. To be able to react to what he does and have the good answer is the real basic of what you have to do. Then, at a good level, you'll be able naturally to feel what he wants to do to and get an extra advantage and that's the point where you feel very strong.
If I had to summarize, you can use the training room against the IA and see what you have to do to make a good shot in the most perfect conditions possible. Then, when you know what you
want to do, wonder
how to do it. And I insist, your thinking must go in this order. The problem is often that you try to find the way to do something but you don't even really know what you're trying to do. You have to be sure of what your goal is step by step if you want to improve your general level.
I point you back to the 3 steps I talked about earlier : moving is essential as it's the #1 part of what you have to do and without that the 2 other parts don't exist. When your opponent hits his shot, remember : either it goes right or left, that's the very first information you get and you have it really fast if you really look at the ball. Then understand how deep the ball will land so you know if you can go into the court or step backwards (For my side I especially changed the settings of my 3d camera so I could understand the fastest possible the deepness of the ball).
Then the position, you want to start aiming only when your position is perfect and where you want to be, even on defense ! (the capacity to hit a good shot in defense is your position, to get the best possible distance between you and the ball so you hit it with the middle of your racket at a good height. Remember that you don't have the time in this case to charge your shot so its quality depends completely on your placement).
And then you charge your shot and put the ball where you want, as close possible to the line without making the fault (on attack at least).
This is exactly my way of thinking on each ball I have to play in this
exact order. Even with the offensive, if I see a short ball, I go into the court to get it at the best position I can have, and
then I charge my shot. It's always better to have a good position and a fewer time to charge than charge long with an average positioning. It's really a step by step matter, you have to work on each of these steps one by one and master each of them perfectly separately, and then to be able to do them naturally on each ball. Also, think that you have to master whatever you use to play, be it a keyboard or a controller : you have to be able to go were you want and do what you want whenever you want. This is essential as the very first thing that links you to the videogame you're playing is that.
And as C4ill said, time is quality here : on each step the fewer time you use the best your shot and level will be. Thinking of going to the net and all other things only makes the difference once you do perfectly the 3 steps I talked about. Once you get this right, you can consider yourself a pretty good player, really. It's only here that the difference between a good player and a player that has something better and can hope for the very top can be seen : after mastering the basic things and do them perfectly, what will be his strategy ? Can he use the netplay at his advantage ? Can he show himself strong mentally ? Can he anticipate and read in his opponent mind ? Can he play the shot he needs at the good moment ? All those sorts of questions, you only have those once you don't have to wonder about what you have to do to play good and make good shots. If you have to think about your execution in a game, it's impossible to do great about the strategy and other things, for one simple reason : how to know if what you did wrong was your strategy or your execution ?
It's like in reality, when you play bad and don't feel your shots, your goal is, as fast as possible, to get back to your basics and find back your good shots, not to become crazy and try some weird things to kill yourself more. But if you feel great, play good shots and yet don't find the solution, it's here you'll think about your strategy for real.

May the genkidama be with you.