I'll share what I've learned from a particular student:
this student has dyslexia (I believe. he has not been tested, but all of his learning hurdles fit that definition).
- limit repertoire. i've learned with this student that it may take 4-6 months to finish a piece at his level. this is because mentally, he doesn't grasp sequence. his visual information gets so jumbled that it's very difficult for him. he may practice a piece every day and play it different every single time. as a result, i purposely buy books that are not dense, so he doesn't feel more pressure than he already does (i.e. kieth snell, essential repertoire).
- LISTEN - the books we use also come with a listening cd. it is SO important for him to constantly listen to his pieces (which he doesn't do that often, unfortunately), to help him sort out sequence problems.
- review, review, review. we review scales and finished pieces every week. since it takes him so long to finish a piece, he doesn't add to his repertoire list very often, but we keep reviewing what he's finished so that he was more to show for all of his efforts.
- the main thing i've learned is that he is much more frustrated with his playing than i am. yes, it's annoying to explain the same concept for the 30th time, but he needs that repetition. he gets flustered very easily and when he loses sense of sequence, he wants to throw his hands up in despair, so alot of our work together is helping him figure out "what to do when you don't know what to do"
hope that helps!