As you see something that yo want to shot and it's bearing down on you, it's important to start framing long before the subject gets close to you. The light will reveal itself possibly long before you want to take the image, but you have to wait until the picture comes to you, and if you've been anticipating carefully when the subject will be in position, the background will have been figured out in advance.
Jay MaiselI try not to tell students where to shoot, when to shoot, or what to shoot. I feel finding the picture is the most important part of being a photographer. The actual shooting is of lesser importance.
Jay Maisel