How to learn for the best results? [closed]

You will need to learn music theory at some point in time.

Here is a reference to the ABRSM piano syllabus:

1. The piano exams">exams are graded from grade 1 to grade 8.
2. For grade 1 to grade 5 exams">exams, you can just take the exam directly.
3. For grade 6 to grade 8 exams">exams, you must first pass a written music theory test before you are allowed to enroll in the exam.

There is a philosophy in this: in the beginning, you are just learning to execute techniques from your teacher. As the score gets more and more complicated, you will need to learn why certain phrases or certain notes are played in a certain way. You need to understand what the composer was thinking to produce better music.

Music theory deals with that. It tells you how the music is structured, how harmony affects the mood of the piece, how one modulates from a major key to a minor key etc. With that knowledge, you can analyze a piece, e.g. when you see a G# in a piece that started in C major, you will know that the composer put that note in because he wanted to get to A minor, which transitions the piece from a happy mood to a sad mood.