Catalog product photography with people can become visually boring if you are not extremely careful. Too many times you end up with models that look out of context or stiff. When directing models for still photography, I try to operate more like a video shoot. I try to come up with something for the talent to do, a simple scenario, and let them go through it at normal speed. More like acting than modeling. It seems to make them more comfortable and hopefully gives a more natural and realistic look.