Hi,
In my experience, try singing the melody line in the Chopin before playing it. Work out all the nuances and then take that to the piano. My tip for the complex cross-rythms is that you should not have to think about the individual hands when playing. You should thoroughly learn each hand and then try to put them together, slowly at first.
Another important thing in Chopin is to not over-pedal. Don't always feel like you need to press the pedal all the way and explore half-pedaling, which is when you press it halfway.
My tip for the Albeniz is to attack the L.H notes with a short, wrist action. Your hands must be relaxed and not tense, as this would really complicate matters. Practise the jump to the big chords slowly, and know where you're going before you need to play them, as looking for them when you should be playing them would take up more time.
Good luck in playing these two beautiful pieces!
Carlos R.