I have a confession: In the figures I have been drawing, the source images often are in the sort of heroic condition that results in veins popping out of their forearms, and I have been pretending those veins are not even there, because I wasn't really sure how to approach drawing them. I figure the first step to learning is to do an extreme-zoom-close-up study of someone's veiny forearm, and here is the result:
For reference, here is a comparison of my sketch to the reference photo:
The main lesson for me is that I tend to get lost in the details of the veins and forget that the actual shape of the arm matters too, so there's some weird warping going on in my drawing. That said, I am pretty happy with how this came out. It will be interesting to see if I can make it happen at the much much smaller scale I need when the main subject is a whole person, not just a close up of his forearm.
Thanks always for looking at my pictures :D