- remove patches of bad lighting
- eliminate unnecessary clutter
- remove a distracting building, head, sign, or pedestrian at the side or corner
- remove sky, grass, beach, or pavement that overwhelms the subject
- put horizons at a line one third or two thirds across the photo (never across the middle)
- make several photos small enough to all fit on a page.
Sometimes I group photos for a page, then crop them. Sometimes I crop a whole stack of photos and then select the groups for each page. Sometimes I flip between the two strategies.