A low angle can be a great way to emphasize difference in height, and it doesn't even require you get super low. When I shot this Father's Day portrait for my best friend and her husband, I sat on the floor a couple feet back from their toddler and angled my lens so I could fit all of Dad in the frame. The end result is an image that emphasizes the fragility of their little man against the strength of his dad. (And given that the toddler will be starting his senior year in high school this fall, I'm not crying, really... )
