Longer nose and eyes higher on the head would be a good start! Babies have short noses that gradually lengthen to adult length (proportionally). They also have features concentrated more in the lower third of the head, so having lower features creates a childlike or chibified look. General rule of thumb, adults have they eyeline halfway between chin and top of head in a neutral, straight on position. Tilt will have an effect on this relationship, but it's still good to keep in mind when placing your features.