I'm new here - thanks for having me. I just learned the joys of creating ACEOs, and I'm in love with it. My most recent ACEOs have been drawn with Prismacolor markers on 8x6" pieces of plastic, then heat processed to shrink them to ACEO size. This allows me to get a lot of detail on such small pieces, and the colors really intensify.
Here is my most recent piece, called "Admiring Venus":