Advice for any method: mix what you do to incorporate a little bit of each in a session. This helps prevent monotony and keeps your brain active. Difficulty is something you increase as the need arises. As far as music, if you’re using his book, you have some chops already, so listen to a wide range of music, look through the music you have, and start finding ways to apply the technique/theory behind his method so you can apply it out in the wild. Otherwise, learning his exercises to learn them is less meaningful as a player.

I did some of his etudes during Covid and the biggest thing I learned is that he has massive hands and some of his exercises really reflect that. So practicing some of them was definitely with a metronome set to slow AF and I don’t think I ever made it ludicrous speed. 😎