1. Have respect
This is my number one rule. It doesn’t matter if I am photographing a poor boy in Laos or the CEO of a large company in New York-I always respect the people I photograph. I live by the motto: “you should never get close to people in order to take their photo; you should take their photo in order to get closer to them”. Act as if your camera is a bridge and not a weapon. I have friends who are amazing street photographers, who manage to work with such discretion that they can get the portrait without the person realizing he was photographed. Certainly, there are some exceptions, but I believe that people are not zebras and we are not hunters. To summarize the point, I photograph old people in same manner I would like someone to take pictures of my grandmother.