I tried jelqing about a year ago, but not on a strict schedule. I noticed a little more vascularity. I've also used improvised cock rings, just for fun, and I've noticed a little more from that, as well. Comparing my current state of penile vascularity now to what it was in my early 20's, I'd say there is a great deal more. I really only notice it on the left side of my penis (the increased vascularity), but that might be I usually masturbate left-handed.