Never pose your subjects. Let them move about naturally... All great photographs today are snapshots.
My trick - is there one? Well, perhaps a bitter youth with many changes of occupation, with the necessity of trying everything from poetry to berry picking. These difficult early years probably constitute the sources of my modest photographic activity.
To see in a thousandth of a second what indifferent people come close to without noticing - that is the principle of photographic reportage. And in the thousandth of a second that follows, to take the photo of what one has seen - that is the practical side of reportage.