I specialize in baby photography—here's a trick I use for family portraits. In traditional setups with two parents and an infant, don't waste your time trying to coax the infant to look at the camera. Instead, place an assistant off-camera in the darkened studio with a large flashlight. Ask the parents to gaze in the direction of the flashlight, and then have the assistant pivot or flicker its beam to attract the baby's attention. When the light catches the baby's eye, fire away. (Avoid having the beam strike a subject.) Then, have the assistant move to another part of the studio, and repeat. You will get many more potential keepers this way, with all three subjects looking, more or less, in the same direction.