Composition after the shot
I try not to think too much about composition when I shoot: I point the camera at whatever I saw, I move around, and press the button whenever it feels right.
It's when I'm back at home that I can see more clearly if the image works or not. Although rare, there are cases where I'll find an image I had not seen in the field, an image I can still make by "re-composing" the original negative or file.
Most of my images are square, as you know. If I'm shooting digital, that means I have to crop the files to that format. While I'd rather shoot square natively, having that extra room for editing has proven to be very useful.
One example is this image of a couple of swans I took in Lago di Garda, in Northern Italy, a few months ago. It was only when I looked at it on the computer that I saw how it could work with a heavy cropping.
Another example is this image of the Badlands National Park, in South Dakota. I'd taken the original photo almost 2 years ago, but it wasn't until recently that I "saw" the panoramic image in it. It was not my intention when I took it, I wasn't thinking about a panorama, but it works.
These are extreme examples, though. Most of the time, all I do is small adjustments to the composition I did manage to capture in the field. For example, take a look at this image of a tree in the italian Alps, and compare it to the original square crop. I decided to place the tree a little bit further to the left, giving the branch a bit more room to grow to the right of the frame.
There's no shame in creating a completely new image after the shot. As I said many times, photography is not a competition, there is no prize for those who get it right the first time. Legends of photography like Ansel Adams kept playing with old negatives for decades, coming up with new edits and interpretations.
Photography is a creative process, inspiration can hit you at any point in your workflow. Embrace it.