Here are some ideas I've seen for recruiting new staff and volunteers. Let's start with one of the behemoths of the anime world: Anime Expo. The convention's 25 years old, their warm bodies attendance count as reported to animecons.com/events is over a hundred thousand, and they're recruiting this weekend at an event in a La Mirada park. (Facebook event page: https://www.facebook.com/events/221164001793352/)
This "AX 2018 Volunteer Recruitment Event" is listed on their website under the "Volunteer" page, so it's not targeted just for Facebook users. Their FB event for Saturday, 2018-03-17, says, in part:
Save the Date! We're having a volunteer recruitment event for Registration, Ticketing, Access Control, Programming Operations
More info about volunteering at AX can be found via our website: https://www.anime-expo.org/get-involved/volunteer/
This isn't the only recruiting/open house event I've seen Anime Expo announce this season, either. In addition to the open events on the occasional Saturday, they've got an easy-to-find entry point on their main web page. You can get to that "More info about volunteering" by following "Get Involved: Volunteer" on their home page.
There's a lot of information on their site, a fairly comprehensive application form, and in general they're hitting all of the marks I've been talking about. They have capsule descriptions for 62 named departments, with requirements and operating hours for each and what they'll do for you depending on your volunteer hours, from four to 40+. I'm going to capture what some of their pages look like so I can file them away for future reference.
Up by Salt Lake City, Anime Banzai is looking for volunteers too -- their website has a number of items that say "(XYZ) Team Needs YOU!" for their Events, Photo, Medical, and Security teams. Some of them then link to signupgenius.com, or various Google Forms.
Something that we tried at Animé Los Angeles was a "job fair"-style recruiting meeting. We had each division represented at their own table, and had a table at the front to allow people to fill out printed or web-based application forms. I thought it went pretty well, but it is a fair amount of work to get every division represented. (Note that Anime Expo's recruiting event just covers four of their 62 departments. Probably more manageable that way.)