I was in a game with a GM that had a Masters in History, who made is a point to mention that the local peasants didn't have wheelbarrows. The rest of the players just shrugged that off but I knew that the GM was trying to tell us the peasants were on the knife edge of starvation.
All that from wheelbarrows? Yes, because before the invention of the wheelbarrow it took two men to carry that load. In it's time the wheelbarrow was the most explosive production multiplier that the peasantry could get their hands on.
This is worth two tips: One about the power of the Wheelbarrow and the other is the moral of the story...that people need to know the point you are trying to make.
Carnival revelers wear masks and concealing clothes. (Wearing of masks in Venice was first documented in the late 1200s) It allows for the social classes to mix, easing social tensions.
Patterns in surnames: There are many ways a surname could have evolved over centuries. One possibility is migration. A Roman name may have traveled to France and hence to England where it was later Anglicized. Case in point - the surname Lawrence went from Laurentius (Roman) to Laurent (French) to Lawrence (English) and then to Lowry (Scottish). There is also natural etymological evolution. For example, a Middle English spelling may have evolved to a modern English spelling (e.g. Stiward to Stewart). Where did your character's Surname come from?
Surnames: Most surnames fall into one of four categories. Patronymic surnames such as Johnson pass from father to son (literally, 'Son of John'). Occupational surnames such as Cook or Miller stem from an individual's livelihood. Topographic names such as Forest or Ford identify habitation. There are also a few surnames that derive from individual characteristics or nicknames...Small and Stern for example.
Surnames: The Chinese were among the very first cultures to adopt the use of hereditary surnames (around 2800 BC). But the custom didn't quite catch on in Europe - at least not until the Venetian aristocracy made it popular sometime between the 10th and 11th centuries AD. What culture made it popular in your setting and why?
In cultures and langauges with very few acceptable personal and family names, nicknames will be used. These nicknames will be based on their physical traits and personalities. So instead of five Ryon Khans, you have Big Ryon, Little Ryon, Fast Ryon, Ryon the Priest, and Ryon with coin. It will make finding people, for an outsider, difficult.
Want to avoid fighter types focusing on swords? Make Longswords and Bastardswords the weapon of the Noble class, with a death penalty for other to carry. These weapons will be ornate and finally crafted. Adventurers will be stuck with cheaply made broad and shortswords, while professional fighters might use two handed swords.
The local temple is known for putting words of wisdom of stele, in and anround the temple. These words of wisdom are normally temple proverbs or wise words, but sometimes they are "singing the praises" of any large contributor or a noble who grants them a special law. If you need proverbs and quotes for them, search a few quote and proverb sites, concentrating on religions like the temples. Put these quotes in a word doc or list, that way you can always "whip out" a bit of wisdom.
No one is allowed to do harm to those of Highest/ Imperial rank, those of the Imperial household or those related within two steps of blood. The second tradition is an executioner must be of a higher rank than those he executes. This leads to "issues" when someone tries to harm a member of the Imperial clan or when these members are subversive. Such people are often killed by the being chained under a giant bell. They die within a day or so from the vibration, but they die untouched by Human hands.
SeaClans: The six seaclans are Dolphin, Gull, Ray, Kraken, Shark, and SeaDragon. These totem animals serve as mascots rather than any deep symbol of the clan. These seafaring organizations are filled with land based saliors and fishermen. They ply the seas and deeper waterways. They function like guilds for ocean sailors
The clans have their own homeland. These people live on large floating rafts- human made islands, as well as vessels of all varieties docked to it. These wetfoots never set foot on land (or only do it for a few hours at most).
Rat Clan: This guild is nominally related to the seaclans. The Rats ply the rivers and marshes of the world, as well as do longshoreman work. The seaclans hold the self proclaimed "rat clan" in contempt and the officials see them as just a Guild of River saliors and longshoremen with a funny name. The Rats hold their title with pride and will take it out on anyone who gives them grief about it.
During a storm the PCs come upon a little boy that plays in the rain. Upon further inspection they discover that he has one eye and a long tongue lolling in its mouth. Spit dripping. It is a demon from beyond that can access our realm during storms, it eats all heads that are not its own, living and dead.