Start with the edge of the frame
It is natural to look first at the main subject of a photograph. The edges deserve a second look. A bright fragment, a half-visible sign or a strong diagonal can pull attention away from the thing you intended to show.
Before taking another picture, move a small distance to either side. Watch how the background changes in relation to the subject. Often a step is more useful than a new camera setting. Keep the horizon deliberate, whether it is straight or tilted.
When reviewing photographs, compare the untrimmed image with one careful crop. Ask what each version includes and excludes, rather than assuming the tighter image is always stronger.