Choosing a cosplay costume often starts with a favorite character, but the real work is finding a version that looks right and feels comfortable enough for a full day at a convention. Online retailers like SimCosplay and Magic Wardrobes carry costume designs from movies, games, and drama series, but the selection is only half the challenge. Getting the details right — from the fit of a superhero cape to the texture of a Jedi tunic — can make the difference between a costume that barely gets worn and one that becomes a go-to for multiple events. Some cosplayers chase screen...