I am a photographer that likes to compose my images full frame in the camera with as little cropping as possible . Often when I'm out photographing especially landscapes, I will already have a pretty good idea of what the composition will look like even before I have my camera set up and have tripped the shutter to capture the exposure, other times composition happens unexpectedly when what I thought was going to work as a great composition just doesn't work, take the example posted, I was photographing at Ellison provincial Park near Vernon BC and was struggling to find the right composition as nothing "felt" quite right, then the camera, being a 4 x 5 view camera on a tripod and on a ball head accidentally slipped over to one side due to the fact I had not tightened the ball head enough, I was looking at looked at the focusing screen when this happened and thought that's it, perfect !
One can Methodically examine the composition of a print and look at what worked and what didn't, but its actually when taking the photograph where everything comes into play and every situation is different. I know what when I'm looking through the view finder of my camera I have a feel for what it should look like, but I can't explain how I got to know what is right or doesn't feel right in terms of compositional balance, its having the right balance of the various elements with in the frame which is the key. I think that looking at the work of other photographers including painters has been a great help to me, I also like to carry with me in my pocket a small plastic card with a frame cut into it to "frame" things up when I am out and about even when I don't have my camera with me, the one I have is made by View Catcher. Often its the interpretation of the scene before me and not trying to put too many elements into the frame but keeping things simple, its often said with photography its not what you put in the frame lines of the camera's viewfinder but its what you leave out.