Take close pictures. As you frame shots, see if you can zoom in or draw nearer to the subject. You want to be sure that the subject area is filled with only the parts of the photo you see fit. A busy background, even a really interesting one, can focus the viewer's eye on it, rather than the subject. Taking photos from close-up also makes details clearer and more noticeable.
Understand that smiling photographs aren't the only kind of pictures. The most effective pictures are those that capture people in their most authentic state. Think of the most memorable images in photographic history: the "Migrant Mother" image of a homeless family during the dust bowl of the depression era, or the visions of young children running and crying when Vietnam fell to the communists. Allowing the
Photography: Learn To Take Masterful Photos Without Training