I will keep that in mind. Even if the matter is entirely personal. One can give general indications, but only the Teacher following the student can suggest the right approach and/or the proportion of time dedicated to this or that study.
Let's say we take a piano technique manual (I would suggest Rossomandi, as it is so well divided into fascicles); one can tackle each single little chapter, not just by repeating it, but by trying to understand which pianistic gestures it refers to. For example, today we study the trill. One will try to internalize the movement that must be performed by the hand. Studying 323232 then 313131 ...535353... etc., internalizing and assimilating the movement and identifying what is wrong in our own execution that prevents us from performing it correctly. I would say that this study can occupy half of the available time at the beginning, then decrease to a third.
During study sessions, one must also study a scale. At the beginning, a scale with sharps will be alternated with one with flats. This should serve as an aid to mentally fix the keys. Besides being technical (starting with contrary motion and then parallel motion), they must first be understood mentally. One sits before the keyboard and enunciates aloud the name of the scale, the accidentals, the leading tone, and the fingers with which it begins and proceeds. Be present during the thumb passage! (which will soon be transformed into "displacement"). It can also be played hands separately. When ready, after mental study, one performs the scale in one breath (either contrary or parallel motion) without interruptions, evaluating only afterwards the incidents that occurred during the concentration process. Naturally, the study must begin with one octave, then two and/or four. This must occupy a portion of the time dedicated to study and technical reflection.
Then Bach and Clementi. Naturally, if there are two lessons per week, one can insist on one of the two authors on alternating weeks. This can occupy a good third of the available time.
The remaining time can be dedicated to an Author of choice, choosing from collections like "my first..."
This could be one of many initial study schemes. It is evident that the Teacher, an irreplaceable figure, will advise on the "right doses." This is also because much depends on learning times and technical and musical progress. Everyone has their own timing, even if we must sometimes be amazed by particular capacities for "assimilation." A Polish pianist friend of mine replaced another pianist who was suddenly indisposed and was supposed to play Liszt's first [concerto]. ..."Fortunately" he received the proposal at two in the afternoon!!!! At nine in the evening... you understood correctly... at 21:00, he played the concerto in public.!!!!! It is a true fact!!! To be closer to us, one day, Simone came to my house to let me listen to, as we often used to do, some parts of his eighth year, prepared boldly and alongside his diploma. It was a study by Moscheles, which he performed with truly excellent speed and clarity. "...I believe it—he said—I studied it all night!!!" Incredible!!!!!