I think my problems haven't been site choice actually, i'm just having problems now with hitting hand veins. I haven't missed an AC or cephalic, or really anything above the hand. I think I have at least a workable technique for advancing the needles and catheters successfully. I think I might not be stabilizing the vein well before poking, letting it slip out of the way as the needle advances. I know i'll figure it out, I just don't want to look like a doaf when i'm trying to do blood draws during clinicals.