When the royal family released their official wedding portrait from Prince Harry’s marriage to Meghan Markle, there was one remarkable feature. Well, a few remarkable features like the Kensington Palace setting and the presence of the Queen of England, but aside from those—practically everyone was smiling.

If you’ve ever tried to take a family picture for a holiday card you know how hard it is to get the young ones smiling on cue. Yet royal wedding photographer Alexi Lubomirski managed to get the young bridesmaids, page boys, and even Prince George and Princess Charlotte to smile sweetly for the camera in unison. His trick is an easy one—and an old one—and you’ll definitely want to borrow it the next time you’re trying to snap a family portrait.

According to Lubomirksi, the royal family’s photo shoot started out like any family’s trip to Sears Portrait Studio. “Some parents were trying to wrangle their children, other uncles and aunts were talking to their nephews and nieces,” Lubomirski revealed in an interview with Reuters. “It was a family, that was essentially what it is.”

However, Lubomirski had a job to do and needed to get everyone settled and smiling and he came armed with a secret weapon. What was it? Candy, lots and lots of candy. “They were being bribed with one Smartie here, one Smartie there, so as soon as the kids came onto the set, I immediately just shouted out ‘Who likes Smarties?’ and then everybody, hands up, smiles, even some adults put their hands up,” Lubomirski shared.

While any candy will likely do the trick, in England Smarties are not the chalky sweets sold in tubes in the South, but are chocolate-filled treats similar to M&Ms. When you’re preparing for your holiday card photo session, fill a purse with peppermint puffs or Chick-O-Sticks or whatever will make your little ones smile on demand.

His willingness to share trade secrets is just one clue that Lubomirksi was raised right, another hint is that he also has excellent manners. On Instagram, he thanked everyone for their shares and support and kind messages during the stressful time in his career, captioning the image: “My parents always taught me to send a thank you note.” While some Southern mamas would not approve of this modern take on the thank-you note, we’ll let it slide.