If you place every element of interest in a photograph on one side or another, leaving little or nothing to look at on the opposite side, the picture is unbalanced, like a seesaw with a child at one end and no one on the other. The best pictures have an inherent balance that makes them look graceful. Photos are frequently put in frames for a good reason: A border around a picture defines the picture's shape and concentrates attention on the image within the frame.
When you're on vacation you may run out of space on your camera's memory card and won't be able to take any more pictures. Fortunately, there are several easy ways to fix this.