One thing that always stands out for me with your work is the line weight. Your lines come across almost digitally made (like a wacom). Hand inking tends to be very organic in feel... it varies due to the various pressing by the user and breathing etc effects it. Your lines however are.... well, damn near perfect! Do you always use ballpoint? Do you go over your lines until they are perfect or do they come out this way in one stroke?
I've used ballpoint, more or less exclusively, for a few years now. The lines don't come out like that in one stroke, though. I block and fill. The areas that are the natural stroke are areas like the shadow under her chin.
If you block and fill (i have done that so understand) then you must be working on a larger paper. I tend to work small so there is no room to accomplish this effect unless I use the ultra small micron's and the trade off is worn out eyes and a headache from squinting. lol. Any particular brand of ball points you favor? I wouldnt mind giving the technique a try one day.