Create a set of diverse AI models representing different ages, races, and mixed ethnicities. The models should embody the theme of approachability, appearing as friendly and relatable individuals you’d feel comfortable saying hi to. All models should be in calm, relaxed poses, looking directly at the camera with warm, welcoming expressions. Each model should be wearing plain, neutral-colored clothes (like t-shirts and jeans) to allow for easy overlay of different designs. The focus should be on the models' authenticity and everyday charm, rather than any glamorous or over-stylized elements.