You have scouted out some picture possibilities and have found fertile ground. Now you actually have to position and aim your camera. For example, let’s say you found a rusting old truck in a farmyard. The truck is the “center” of the image, though it doesn’t have to be positioned that way. Let’s say that for this image, you have decided to photograph the truck while showing its environment in the background, rather than coming in close.
You have a choice of photographing the truck surrounded by farm buildings, or with a harvested grain field in the background. The choice you make will determine the character of the image. In this case, you try for the grain field because the farmyard is full of old machinery.
You wander around the truck looking for the best angle from which to photograph and to determine what will show in the background. Unless you want the junkyard look (and you might), you will want to simplify both background and foreground to help keep the main focus on the truck. Modern buildings or objects are not going to work well with the truck. Can you find an angle from which to shoot where the truck works well with the background?
Let’s say that, despite your best efforts, the backgrounds are all absolutely terrible. You can’t get a clear shot of the field due to telephone wires, there isn’t a nice weathered barn against which ...