Among the many qualities people say are required of a leader, humor usually doesn't list in the top ten. From my experience, I believe having a great sense of humor and the ability to take yourself lightly is essential to working with your team.
Of my five or so years post-college, I've been working with volunteers 100% of the time. A majority of that consisted of volunteer musicians, singers and choir members, and more recently media volunteers. One of the hardest things when working with volunteers is giving constructive criticism or correction. You think, "these people are serving out of the goodness of their heart, and I'm going to tell them they're doing something wrong?"
That's where humor comes in.
I've always believed I'm somewhat of a funny guy, and whether or not that's true I do everything I can to make sure people laugh when they work with me. Not only does laughter help you relate to a person and develops a level of trust, it can open the door for critique. It's a lot easier to make a choir laugh at their own mistake than it is to point blankly expose their error with no covering of laughter.
Same with media. If the person running ProPresenter misses a cue, you have the option to say, "What happened? Make sure we get that next time. We can't miss that next service!" or you can say, "Out late partying last night eh?" (In a jovial tone of course).
When you've laughed together with your team, critiques and issues can be resolved light heartedly, but with the same precision. Humor doesn't need to encompass every conversation, but a healthy, regular dose of laughter can cover a multitude of criticism.