In some regions, various occupations might be exclusively staffed by members of a particular race or ethnic group. As examples, a city's butchers might tradtionally have orcish blood, or all the dwarves in an area could be expected to join the miners' guild (even if they personally have nothing to do with mining). Those who violate these stereotypes may find themselves in conflict with local customs or idiosyncratic laws.
On some of the islands off the coast, the rites of the local fertility god revolve around ceremonial death and rebirth. The religion's priests have overcome this cycle, however: Each of them is actually undead, ceremonially slain and "reborn"! Their religion is otherwise unremarkable, being an odd offshoot of the mainland's religions. The priests vow to resist their undead cravings, seeing these as the "cycle of life" attempting to reclaim their spirits.
According to the Journals of Lord Goidol, the people of the Southern Cities wear heavy coats all the year round, despite the stifling tropical heat. They claim that to do otherwise angers the gods, and it is true that visitors who refuse to don the local garb are often struck down with a paralytic fever.
There is a land where every person wears spectacles. Those without eyeglasses are considered to be the lowest stratum of society, so adventurers without glasses are treated like outcastes. It certainly would explain those heroes wearing sunglasses for no apparent reason...
In a city where the justice system features judicial dueling, plaintiffs and defendants are permitted to request a champion to take their place in the duel: Someone chosen by lot from among the foreigners in the city. When anyone first arrives, they are given an enchanted ceramic pendant that marks them as a candidate for "court duty".
Wealthy folk entering the city are often escorted by burly guards, paid to carry pendants on their behalf: They elude court duty in that way.
Adventurers may seek work as a rich man's proxy or may find themselves magically summoned to serve as a champion.
In an isolated mountainous region, the local miners build their stone huts right next to the sarcophagi of their dead. In the winding tunnels of their mines, the spirits of their ancestors toil alongside them, sensing where the best deposits will be found and guiding their picks' strokes.
The Nomin gypsies have a fiddling competition every year, known as the Danse de Velose. Beaters hit out the rhythm on taut drums and the competitors start to play, slowly at first. Youngsters can compete, but are soon pulled away by worried mothers, before the competition becomes too dangerous. After two hours the haunting tune has become dazzlingly fast. You can resign at any time, but the moment you make a mistake you receive an arrow through the neck. Strings may snap, but the players must play on. The whole affair never lasts much longer than three hours, and the last fiddler playing is crowned king of the gypsies.