Combining travel with volunteering can be the most memorable part of a trip — or an awkward photo opportunity that helps no one. The difference is who sets the agenda.

Follow the local lead

The best projects are designed and run by local organizations that would be doing the work with or without visitors. Your job is to add hands, not direction. Ask what is needed before you offer what you have.

Three questions to ask before you book

• Does the organization work here year-round, with local staff?

• Would this task exist if no travelers came — or was it invented for them?

• Are you skilled enough that your help costs less than it gives?

Done right, a service day abroad turns a destination into a place you genuinely know — and a community you keep in touch with long after the flight home.