You can use em dashes to expand on a point of interest—like the list of examples in the snippet below.
Whatever the reason, it seemed that just about everyone in Welch—men, women, boys, girls—liked to fight.
Notice how in this case the expansion happens in the middle—not the end—of the sentence.
Whatever the reason, it seemed that just about all my friends—Solly, Hamish, Suki and Jacqueline—had gotten into Mexican wrestling.
Whatever the reason, it seemed that just about everyone in the school—juniors, seniors, teachers, cleaners—liked to krump.
I don't know how it started, but by the end of the day Jonno had drawn dinosaurs—herbivores, carnivores, omnivores, even detritivores—all through the boys' toilets.
