Index cards were used mainly for the sake of portability; I can also easily write additional information on them (Drawings, reminders, etc.) to help cement the ChinaTown locations in my head. Soon, new vocabulary words will go straight into Supermemo with no middle-man.
A couple of things I noticed:
-If I stress the location of the character, words come much quicker. The words I found to be the most difficult to remember all involve characters that have a somewhat "hazy" location. In other words, ambiguous location = ambiguous retention.
-Tones are not posing a difficulty. After reviewing a word a few times, the tones come naturally.
I'll update you again as I experiment more rigorously with remembering Chinese vocabulary.