Whenever you get corrections in class, how do you set priorities for fixing them? For example, if you get a correction while doing demi or grand plie, that's a priority to fix, because it will affect everything else you do.
Especially in pointe shoes, a flaw in how you do a plie will affect your posture, balance, strength of turnout, and go on to affect pirouettes and more.
It will also affect your allegro, or jumps.
If you get a correction later in the ballet barre work, that may be where your ballet teacher first noticed the error, in that class.
However, if your dance teacher does not address it further, it is up to you to figure out where in the basic ballet positions, ballet movements, or ballet technique, you need to go, to fix your correction.
As an example, if your teacher corrects tense or "spiky" fingers during a ronde de jambe a terre combination, you need to (after class) back-peddle mentally to figure out why your fingers are tense looking.
Relaxed hands and fingers are the result of strength in the core muscles. If the core muscles are strong enough to support posture, turnout and ballet positions, then there will not be any extra tension traveling to the neck, shoulders, and down the arms to the hands.
So, as your own experiment, see if there is any strain in your plie exercises in class. Do you understand what muscles should be working hard, and relaxing, at what point during the exercise? Tension in ballet is FLUID. It is always changing.
Understanding plies and tendus, in ballet, will lead to your understanding every aspect of ballet technique. Posture, turnout and balance are all equally important parts of ballet technique (including the proper use of the intrinsic foot muscles for demi pointe and full pointe). And most other dance techniques, not to mention football, tennis and more. (Tennis pros and football teams study ballet to develop footwork and prevent sports injuries). It's all about doing what the body can do, and not trying to make it do what it cannot do.
Try to relate all your corrections back to your basic ballet movements. If you can fix the most basic flaws in your ballet technique, you will fix many things that can go wrong in a ballet class.
Dancing ballet successfully does not depend on perfection. It does depend on you understanding how close to the ideal you are. And, what keeps you from the ideal - physique, muscle weakness, or lack of technical comprehension. I've taught ten year olds who had this sorted out within months of starting training in classical ballet. Something just clicked for them that way.
So wherever you are in your ballet training, start right now to analyze and set your priorities with your corrections in ballet class. Pick the most basic correction that you get, and focus on it. To understand ballet barre exercises, get THE BALLET BIBLE.