I have been practicing these for quite a while at the same time and none of them seem to be improving that much... 
How do you practise them at the moment? Do you play through them just once, and then move onto the next?
I would take one at a time, study them away from the piano, dividing them into their forms, highlighting important motifs etc. Then play these sections, left hand, then right hand, AT LEAST five times each, starting slow, and increasing in tempo time. If you find you are making certain mistakes, take just the bar before and the bar after, and really slow everything down. Once you;ve got everything right, do it again another three times.
Gradually put the pieces together again like a jigsaw puzzle.
Playing through pieces in their entirety doesn't always make for progress.
But, it's hard to give specific tips without knowing exactly what you're doing first.
Anyway, let us know how your piano camp goes.
