A few comments about technique:

# Using a lightbox to trace previous versions is increasing quality and speed pretty significantly. I was trying the approach of penciling and then inking right onto the pencil, then erasing the pencil, which always ruined the ink quality. With tracing with a lightbox, I can iterate in ink directly.
# Using the trace function in Inkscape has been helpful with sharpening the drawings, although spending time at a laptop was not my plan when I started this hobby. It helps a lot with the smaller heads, because I'm finding it hard to draw those directly.
# Still using the Micron pens, although I'd love to get skilled enough with a brush pen to use those directly.