People should not be in distracting poses, or have facial expressions that attract attention from the viewer.
People should generally not be placed too close to the camera, such that it becomes completely obvious that they are 3d models. It is possible now to use Stable Diffusion to enhance foreground people.
Small groups of people should appear to be socializing with each other
Clothing, general appearance should match the project design. Casual? Dressed up? Athletic? Swim suits? Poor? Wealthy?
In the U.S. it is important to show diversity in skin color and nationality. We can’t have all people with white skin and blond hair. Add African American, Asian, Indian, or Mexican people. Apply this to at least 30% of visible people.