Having learned all but 3 of the etudes by now, I'll try to come with some more helpful comments about the ones I hadn't learned when I wrote here the last time.
Nr. 2 - Thirds
For me, one of the studies from book 1 that took the most time to learn thoroughly. First of all, it should not be played too fast, it is marked sostenuto and legato (please avoid Uchida's recording of this particular etude), and while an etude in thirds immediately makes you think of Chopin's op. 25 nr 6, this one requires a different approach altogether. In Chopin, because of the fast tempo, the overall approach is to play the top voice of the thirds legato, the lower less legato, almost staccato even. The slower tempo of the Debussy study, however, suggests that you indeed must do your best, even when it is not physically possible, to connect BOTH voices. For any pianist, working on finding the best fingerings is going to take time - I figured out many things myself, but also had a look at various editions for suggestions. Every single bar presents different challenges and many variants on fingerings. And ultimately, you have to remember that it should be a beautiful piece of flowing music even though, in a Chopinian fashion, the piece hardly ever breaks the flow of steady 16th-notes. It easily starts to sound too much like an etude, and that's not what we want here, ever. Ultimately, it's an incredible piece of music and truly rewarding to work on.
Nr. 3 - Fourths
This is a very peculiar piece, mixing all sorts of Debussian elements. As a pianist I knew who actually performed the complete piano works by Debussy, it is a bit difficult to adjust to playing fourths after a study in thirds! In any case, most of this etude presents the same difficulties that we find in most of Debussy's piano music - having an ear for colour, pedaling, and touch, is more important than anything else, and most of this etude is really not that hard to play. The fourth-runs in the stretto section and in the accelerando part later on in the piece might take a while to master. Yet another very rewarding etude to learn! Memorization might take a little while, but fingering is not nearly as much of a problem here comparing to the previous etude.
Nr. 4 - Sixths
One of the etudes I first found the least interesting, but eventually, I found myself at home with this piece. It is partly a study in strongly connected legato sixths, and finding the most suitable fingering is very important - again, connect both voices as much as possible. Depending on how slow you want it to be, you might be able to change fingers on both sixths going from one note to the next - that gives a smooth legato in my opinion. It is also partly a study in playing sixths from the wrist. Once you've made your way through the faster sections, written down fingerings, it is all quite easy to play actually. Again, listening to the sound quality is very important, and to differentiate between different voices, especially towards the end.
Nr. 6 - For the 8 fingers
Still a work in progress for me - a fun piece to play and to listen to, but rather challenging in its demand for clarity and speed. Like my teacher said - one should STRIVE for clarity, but in the required tempo, it WILL sound somewhat unclear no matter how you play it. Also, as most who have looked into the etudes knows - very few actually play the entire piece with 8 fingers. It works about 70-80% of the time, but in several places you can arrange things differently for comfort and clarity.
Nr. 10 - Opposing sonorities
One of the most beautiful etudes, and in addition, one of the easiest to learn and play. The main challenge lies in using different touch for different registers. One should also think about if Debussy would have taken advantage of the middle pedal in a piece like this? Or should it be played according to what Debussy knew? Just look at the opening of this piece - by using the middle pedal for the top notes, you could actually release the later notes when they are supposed to be released, rather than holding them with pedal. To some, this sounds dry and ugly...but maybe it is worth having in mind, when studying this piece. And some of the other etudes for that matter, I use the middle pedal in the thirds study, possibly in the fourths study in a place or two as well.
Alright, will write about the 3 remaining etudes once I have learned them!!!
