You are photographing on a busy street. You are taking a variety of pictures, including photographs with people in them. What should you do?
In a public place, it is best to be casual about it. It is not necessary that you ask each person who will be included in your shot be asked for consent but if somebody expresses that they do not want to be taken a photo of, then take that into consideration.
You are photographing in a park. You notice that the backyard next to the park may have some interesting photograph possibilities. What should you do?
If you take a photo of a private property, ask for permission.
You are on vacation and see an old man sitting by the sea. You think this would make a great photograph. What should you do?
When taking a portrait of a person, always ask for their permission first.