I hate bad meetings. So, if i call a big meeting, I often design "placemats". I believe the right scope for any 2 hour workshop is about what you can fit on one A3 page. Placemats likes these keep everyone on the same page (literally). They're data driven, and they follow an agenda that leads the group from facts, through discussion, to solutions. They take an hour or two to design, but I think if you're going to get a room full of executives together, the effort is worth it. I'm happy to spend time to avoid waasting everyone else's time.
I also design placemats for orientation events, like the one below.