Though Labor Day marks the unofficial end to summer, its true purpose is to recognize the contributions that America’s workers make on a daily basis. You should certainly use this as an occasion to thank your mail deliverer, your doctor, your mechanic and anyone else whose work makes your life better, but it’s important to not forget an entire category of people whose contributions often go unnoticed: nonprofit workers.

When you’re hitting the beach, firing up the barbecue or relaxing with a good book next week, remember to take some time to thank the people who are behind-the-scenes at organizations that accomplish amazing things in the United States and globally. Consider making one of these simple gestures:

Ask them if there’s anything you can do to help. Volunteering with a nonprofit is a great way to aid the organization’s employees, but sometimes there are necessary tasks or projects that aren’t being completed through the existing volunteer program. Instead of just contributing through donations or a day of volunteering, offer up your unique skills and expertise to the nonprofit. If you’re a marketing expert or graphic designer, consider designing a campaign for the nonprofit’s upcoming fundraiser. If you have connections in the corporate world, offer to find sponsors or speakers for a new event. Your thoughtful questions and ideas will show how deeply you appreciate the people who make that nonprofit possible.

Support them in their mission. If the nonprofit of your choice has individual workers who need financial backing, consider putting part or all of your monthly donation budget to their cause. By focusing your charitable contributions on one specific person, you can help further the work that they’re doing and convey just how valuable you think it is.

Write them a thank-you note. It might seem like people who serve such important causes would be thanked frequently, but that isn’t always the case. Take some time to write a thoughtful note to a nonprofit worker expressing why you’re grateful for the work that they do. If you can include how their selfless actions have impacted your life or the life of someone close to you, that’s even better.