For many travelers, hiring a private tour guide is a luxury. But with an informed approach, it’s an expense that’s often worth the cost. “With a good guide, you will learn and see things that you would never find in a book or online,” said Emma Guest-Consales, vice president of the Guides Association of New York City and a private tour guide.

But how do you find the best one for you? Here are some tips.

>> Turn to a local guide association: Most major cities around the world have a local guide association that have a network of licensed guides to pick from. Guides Association of New York City’s guides, for example, are licensed by the New York City Department of Consumer Affairs. These organizations, Guest-Consales said, are good sources, and their websites often allow you to search for one based on your interests such as food or history and, should you need one, a guide that speaks multiple languages.

“Anyone can call him or herself a guide,” Guest-Consales said, “but you want to make sure that the person you are contracting is licensed.” Also, popular guides often have reviews on TripAdvisor, which is another source for verification.

>> Use the guides already available at tourist attractions: Many major landmarks and museums offer private tours, Guest-Consales said. These are led by guides who have extensive knowledge of that attraction. Most of these attractions require that their guides go through several months of training before they’re allowed to give tours, and if you’re looking for a customized, in-depth perspective of a particular site, hiring one is the way to go.

>> Rely on your network or ask your hotel concierge: Asking your social media network for suggestions is another way to go. You can also ask your hotel concierge for names of local guides. If you’re not staying at a hotel, you can still reach out to the concierge staff at a property in town and request names.

However, do your homework with any guide, even one recommended by a hotel concierge. Many guides have agreements with concierges or hotels who are paid to steer travelers to pricey tourist traps. By policy, reputable hotels reject such agreements, but there’s no accounting for individual relationships. A recommendation from a hotel or resort is no substitute for asking the right questions.

>> Know what you need in a local guide: Some guides who focus on art, for example, have degrees in art history while culinary specialists may be former chefs. That means your tour with them has the potential to be much richer.

When reaching out to a potential guide, be specific on exactly what you want from the tour. Be sure to communicate the dates, amount of time you want to spend and number of people you’d like to bring on your tour. If the guide can’t accommodate you, they may know someone who can.