@annachronism
tyty. I draw these sprites with the binary pen tool in SAI, which draws hard-edged lines, shown here next to a line drawn with a regular pen tool.
after that, it's a matter of drawing the image at a resolution small enough that the individual pixels are visible to the eye, but large enough to show details. I found a good balance mostly by trial and error. I hope I was able to explain this well enough.
https://this.mouse.rocks/media/sccsE1RaGt4Yuyi31M4