I work in film and television and when I do photoshoots with actors it is critical that I keep in mind that their time is very expensive. I generate an accurate shot list that includes a predetermined lighting plot for each setup (including levels etc....) and I send hair, makeup and wardrobe a schedule and a shot list that includes all the information that they need to know. I don't do story boards, but I often print reference material and make an "inspiration board" that gives models (in my case, actors) a solid idea of what I need in terms of poses and expressions. If I have several people to shoot, I hire a coordinator to organize and send all pertinent information to all people, and then wrangle the actors for me on set, which frees me up to concentrate on the photography instead of the coordination effort. When shooting with multiple models, planning is everything... you need to be in a position where you can have them sent in for their session, shoot them out, and move on... with no decision making or problem solving going on at all... it should all be very fluid and very well organized.... and when it is, the results of that effort are reflected in the quality of the photos themselves.