You're going to think I'm stupid, but here's my plan:
1. Tuition reimbursement grants. If you want highly trained staff, help pay for it. Require that those that get grants volunteer x hours.
2. Make people want to come to the station. I worked in a suburban city that had several all volunteer fire stations. They were an all-volunteer city with no compensation besides some money if you volunteer 20+ years. Their response times were amazing, because the stations were great. They had big TVs, snack food, and a cool living place where people tended to hang out. If you build it, they will come!
3. Volunteer recognition. You're going to think this sounds stupid, but I've found in every job people want to be recognized for what they do. Maybe a "Volunteer of the Quarter/Month," or some other recognition, I'm telling you, it works! Get a few local places to throw together a prize package, get a nice certificate framed for $5 total, and you're ready to go. Recognize volunteers for doing things you want, and you'll see more people do it. Maybe one volunteer will be picked at random for a $25 gas gift card. Team up with a local sports team, they love to give out tickets for volunteer agencies.
4. Ask your volunteers what they think. Sometimes I've have a great idea or be so insulated in a project I'll implement something that doesn't go over so well. Now I get feedback from my entire audience/group, and it's amazing what they have to say. Take it all in, write it down, and then evaluate it.
I hope that helps.