Something catches your eye, or your interest. You attack it in some way or observe it in some way, and try to put it in some kind of form and take a picture. It's as simple as that.
Elliott ErwittTo me, photography is an art of observation. It's about finding something interesting in an ordinary place... I've found it has little to do with the things you see and everything to do with the way you see them.
Elliott Erwitt