1) Get out of the concessions business -- use food trucks instead.
Concessions are low-profit, high risk and take a lot of volunteers to run. Instead, hire a food truck to come and feed your folk -- the food may be better, and it's a lot more fun. Some vendors will even give you a small cut of their revenue from your event.
2) Move your volunteer sign ups online. Use SignUpGenius or VolunteerSpot. You no longer have to nag the same people to get volunteers. Your volunteer base will be wider. Added bonus: after a year, you'll have a record of how many volunteers you used last time!
3) Hold Spirit Nights. Spirit nights are events where your community shows up at a restaurant or entertainment venue to have fun together, and your PTA gets a cut of the money they spend. Our most successful spirit nights were roller skating -- fun for the whole family, healthy, low cost. All you have to do schedule the event and promote. (Some require teacher participation -- which is more work.)
4) Limit your spirit gear. "Spirit gear" -- t-shirts, coozies, sweatshirts, key rings, bags etc with your school's name on them. Inventory management is not simple, nor is it fun. Simplify this job by limiting your gear to a single shape & color of t-shirt. It's enough.
5) Limit your fundraisers. Pick the one that is the most profitable and/or "honest" and put a lot of effort behind it. Fundraisers are also a ton of work -- even the "easy" ones. Do one, and put a lot of effort into making it successful. If you're going to work that hard, make it one that feels "right", rather than a peer pressure project.
6) Look for high impact work. For us this was grants & community sponsorship. Find strong individuals to run that work.
7) Tie meetings in to school events -- and keep them short. Related -- find out the smallest number of general meetings you are required to have per your bylaws, and just have that many. Publicize board meetings or committee meetings for people who want to be involved. Consider sending out meeting minutes from board meetings via e-mail to keep people informed.
8) Provide information in as many ways as possible, but focus on electronic rather than physical media -- on a website, facebook, and an email list.
9) See if you can use your school's phone system to inform parents of events. This was our biggest PR win -- sending out voice alerts the afternoon before an event. I never tested it, but suspect that we could have done this and skipped newseletters, stickers, etc.
