Every team has the loud ones and the quiet ones. Those who jump right in, and those who observe first. The question is: how do you build an event where both sides don't just attend, but actually participate?
Different roles, no pressure
At a film event, there's acting, directing, camera, story, set, organization. If you like performing, you go in front of the camera. If you prefer keeping an overview, you take on directing or handle the set. Nobody gets pushed into a role that doesn't fit.
Sounds obvious, but it isn't the case at many team events. How often do you stand somewhere thinking: this just isn't my thing.
Small teams help
Even with large groups, you work in small film crews. That takes the pressure off, especially for quieter people. You don't have to prove yourself in front of 80 people - you work with 8 or 10. That makes a big difference.