I have found responsibility to be one of the greatest motivators, both for me personally and for employees. Making a person feel directly responsible for the task they are given engages them more and pushes them to excel at what they are doing - I'm tempted to say, because it sparks a sense of ownership.

I don't think it's necessary to share every detail either. I just believe that by strategically sharing key details with the right people, they will feel more involved and personally responsible. A part of that might actually even have to do with them feeling trusted and appreciated... which I think goes a long way.

Engaging single employees on a personal level obviously becomes more difficult the larger the team grows. You can't share every detail with everyone, and it can, at times, be very time consuming to manage this kind of relationship with everyone. But there are ways to handle this for large teams as well - perhaps by involving the team as a whole, and/or by designating a team manager, among other things.