Process: I decided to leave the ink spots in this image to give it a bit more of a loose or possibly creepy feeling.
These ink spots are actually quite timid when compared to Ralph Steadman ink spots, but there you go.
They happen like this:
I draw mostly on a "Mnemosyne" pad by Maruman. The Mnemosyne is one of two indulgences I reward myself with for being a good little artist and turning out an image a day.
I take an initial stab at an image in ballpoint pen, then when that doesn't work, I break out the pencil. Once I have a drawing that seems reasonable, I trace over the pencil lines with an Ultra Fine Point Sharpie. It is this ink which occasionally bleeds through to the next page where it waits to be included in the next scan.
Usually, I remove the spots in the GIMP before I pull the image into Inkscape for coloring.