If you're looking for the biggest return on investment, from a "Time Spent Volunteering" :: "Awesome Results" perpective, you're probably looking for Rigging Security. You're helping make fireworks happen. Fireworks man! You love fireworks. I know that because you're a people, and people love fireworks.
Other volunteer shifts are important, no doubt. But come on man, be serious. Bang for your buck? It's not even a conversation. It's Rigging Security all the way.
Volunteers in this role help make sure that the on-site fireworks rigging, which prepares the fireworks that get set off during the nighttime art burns, are done in a safe and secure environment. You'll notify other burners of the rigging area so that the fireworks can be set up undisturbed.
Burners who enter the rigging area tend to do so accidentally, so this is a fairly low-intensity role compared with its impact on the safety of the burn. Despite the word "security" in the title, you don't have to be tough or a jerk. You're just making sure people know where they shouldn't be while fireworks are being worked on.
Like many other volunteer roles at Constellation, you'll be exposed to the elements during your shift. You'll probably be stationary for most of it, but depending on the needs of your department lead, you may be dissuaded from sitting while you're volunteering.
Fireworks rigging will be done in the front field. You can report straight there, or come to nearby Volunteer HQ if you need pointed in the right direction.
Good to bring: water, sun/weather protection, a chair (with the understanding that you may not be able to use it)