If a subject has a delicate surface to it, you do not want to go charging in there. You need to establish some kind of presence and understanding. I will say, Try to forget I'm here. I won't ask you to pose, I won't ask you to do anything. It's important that I just be allowed to be around, to be present. Photographing people requires a willingness to be rejected. So, I think the best approach is to be honest and direct. Very often, I tell them, You don't know me. There's no reason why you should trust me... the only thing I can promise is that I'll try to do the most honest work I can.