Maybe one of the volunteer poems below. Eithter making a card with the poem on it, or reading it to the group.

Here is a link that might be useful: Volunteer Poems

Be sure to acknowledge them if possible in a public place for their service...announce it, put their names in booklets, newsletters, etc.

Thank them immediatly, always for a job done, for their time and for giving their time....the most precious gift of all. Let them know that without them YOU would not have a job, and that you are grateful.
Letters to the editor in a local paper are good. Volunteers are just that....we don't look for "awards" not framed plaques, nor an invitation to an appreciation luncheon.
Linda C

I'd actually prefer a sincere, promptly written thank you note to a plaque or certificate or annual recognition doodad.

(And I work for a non-profit as well, I know how long the list of people to thank can be after an event. Newsletters, event programs, acknowledgement from the podium, etc are all good too)

I think that a personal letter -- not a form letter -- preferably hand-written, would mean more to me than anything. If there are just too many for one person to do them all, at least try to get your helpers to be people who know what the people did, so they can say something individual to each.

I have volunteered for a number of non profits over the year, and my favorite acknowledgment has always, and continues to be, a hand written note expressing thanks for my time and energy. I have never liked volunteer luncheons or anything along those lines.

I agree, a heartfelt note is much more a thank you than anything else..
I volunteer in several organizations and capacities...
I don't like the "parties" and don't attend.

I also appreciate it when someone takes the time to say..we know xyz would not be possible without your time and effort..

We have a large annual event and provide a "Volunteer Lounge" for that years crop of volunteers. It has confortable seating, cold drinks and coffee as well as a Wi-Fi connection and available staff ( a temp) to help with anything for them.

The most important recognition is a thank you!