We've all been part of groups or clubs. Rotary club (does that still exist?), Dead Gamers Societies (that's still around, right?), softball teams (go Midgets!), Lost Boys, Girl Scouts (cooooookies), Indian Maidens (Indian Princesses? I don't remember), whatever they call that group in Eyes Wide Shut (that wasn't just me, was it? Why is somebody wearing a chipmunk mask?? Why??? Oh... wait that was in The Shining...).
Think of some groups you have not been a member of, especially fictional groups. Argonauts (with that hotshot Jason), Lost Boys, Merry Men (they were TIGHT tights), the Untouchables, the Seven Dwarves.
Write in the voice of a nameless member of that group and what it brings to them. A sense of belonging, or maybe a sense of not fitting in. What does it feel like to belong, or to be labeled? How does this group define who you are?