Here's an exercise for you to try.Since you want to stay in Am diatonic (harmonic, melodic, natural...? You can use all 3 if you want), just pick whatever chords you want.Practice leading through the chords that you want, avoiding parallel 5ths or octaves IN THE SAME VOICE, and using as much contrary motion as possible. Make the steps in each voice as small as possible. You can do a lot with this. Try to avoid the flat ninths, and spell the chords with the larger intervals on the bottom, unless you're going for a really specific effect.Example:A E A C (Am, standard harmonic series voicing without the octave at the bottom)E E G# D (E7, usually it's standard to omit the 5th if you have to leave a note out)D F B D (Bdim)C G B E (CM7, the C and G are a 12th apart)Not the best in the world, but a quick example on my lunch break LOL
Very nice exercise. BTW, I would choose Scriabin Sonata 4.