Accuracy develops through corrections and awareness.
The teacher corrects your form.
Your capacity to understand and implement those corrections is directly linked to how receptive, observant and attentive you are.
If you are prideful, stubborn or lazy, you will not make changes to your form.
Awareness is something that needs to be cultivated.
It involves having an eye for the art, for perceiving what the teacher is actually doing. Not what you think they are doing.