If you want to have the "perfect" picture, I suggest you hire actors and actresses to protray your family. Because in the real world you get what you've got. They may have short attention spans, get distracted easily, have trouble following instructions and prefer to look "natural". You know that look that only a mother "has" to love? But they are yours, so enjoy them, go with the flow, make a memory and create something you can blackmail them with later.