Random linguistic worldbuilding: A language with six sets of pronouns, which are set by one's current state of existence. There's a separate pronoun for people who are alive, people who are dead, and potential future people who are yet to be born, and the ambiguous ones of "may or may not be alive or aleady dead", "may or may not have even been born yet", and the ultimate general/ambiguous all-covering one that covers all ambiguous states.

The culture has a specific defined term for that tragic span of time when a widow keeps accidentally referring to their spouse with living pronouns. New parents-to-be dropping the happy surprise news of a pregnancy by referring to their future child with the "is yet to be born" pronoun instead of a more ambiguous one and waiting for the "wait what did you just say?" reactions.

Someone jokingly referring to themselves with the dead person pronouns just to highlight how horrible their current hangover is. A notorious aspiring ladies' man who keeps trying to pursue women in their 20s despite of approaching middle age fails to notice the insult when someone asks him when he's planning to get married, and uses the pronoun that implies that his ideal future bride may not even be born yet.

A mother whose young adult child just moved away from home for the first time, who continues to dramatically refer to their child with "may or may not be already dead" until the aforementioned child replies to her on facebook like "ma stop telling people I'm dead" and having her respond with "well how could I possibly know that when you don't even write to us? >:,C"

I would be such a good high priestess in a fantasy world. I would be great at walking about in veils and only speaking loudly during important ceremonies, otherwise whispering short sentences into the ears of my holy attendants to speak for me. I'd be awesome at holding aloft a chalice of blessed water and/or blood and maybe even guarding a dark secret about how the god we all worship is actually evil and we're totally gonna sacrifice that wounded hero we just nursed back to health after finding him in the forest surrounded by thirty slain wolves.

I would still do all my unhinged Tumblr posting but it would be in a secret diary hidden within the walls of my holy bedchamber, undiscovered until the temple collapses when the sacrifice goes wrong. So no worries there, you'd get my posts late and all at once is all.

How fucked up would it be if you woke up one morning and everyone was the exact same height relative to age. Like all ten-year-olds were the same height, all eleven-year-olds slightly taller, all adults who had finished growing? Exact same height baby. People whp lost their legs would be appropriately shorter but would find that their prosthetics, if they use them, ate sized to make them the same height as everyone else. Wheelchairs? Well I guess they have to stay chair sized so they're easy to actually use, but everyone else is at eye level.

I'm not going anywhere profound with this I just think the fallout would be funny as hell. Admittedly clothing sizing would become easier on one axis.

There used to be a lot of activities that took place around a populated area like a village or town, which you would encounter before you reached the town itself. Most of those crafts have either been eliminated in the developed world or now take place out of view on private land, and so modern authors don't think of them when creating fantasy worlds or writing historical fiction. I think that sprinkling those in could both enrich the worlds you're writing in and, potentially, add useful plot devices.

For example, your travelers might know that they're near civilization when they start finding trees in the woods that have been tapped, for pitch or for sap. They might find a forester's trap line and trace it back to his hut to get medical care. Maybe they retrace the passage of a peasant and his pig out hunting for truffles. If they're coming along a coast, maybe your travelers come across the pools where sea water is dried down to salt, or the furnaces where bog iron ore is smelted.

Maybe they see a column of smoke and follow it to the house-sized kilns of a potter's yard where men work making bricks or roof tiles. From miles away they could smell the unmistakeable odor of pine sap being rendered down into pitch, and follow that to a village. Or they hear the flute playing of a shepherd boy whiling away the hours in the high pasture.

They could find the clearing where the charcoal burners recently broke down an earth kiln, and follow the hoof prints and drag marks of their horse and sledge as they hauled the charcoal back to civilization. Or follow the sound of metal on stone to a quarry or gravel pit. Maybe they know they're nearly to town when they come across a clay bank with signs of recent clay gathering.

Of course around every town and city there will be farms, more densely packed the closer you are. But don't just think of fields of grains or vegetables. Think of managed woodlands, like maybe trees coppiced-- cut and then regrown--to customize the shape or size of the branches. Cows being grazed in a communal green. Waiting as a huge flock of ducks is driven across the road. Orchards in bloom.

If they're approaching by road, there will be things best done out of town. The threshing floor where grain is beaten with flails or run through crushing wheels to separate the grain from its casing, and then winnowed, using the wind to carry away the chaff. Laundresses working in the river, their linens bleaching on the grass at the drying yard. The stench of the tanners, barred from town for stinking so badly. The rushing wheel-race and great creaking wheel of the flour mill.

If it's a larger town, there might be a livestock market outside the gates, with goats milling in woven willow pens or chickens in wooden cages. Or a line of horses for the wealthier buyer or your desperate travelers. There might be a red light district, escaping the regulations of the city proper, or plain old slums. More industrial yards, like the yards where fabric is dyed (these might also smell quite bad, like rotting plant material, or urine).

There are so many things that preindustrial people did and would find familiar that we just don't know about now. So much of life was lived out in the open for anyone to see. Make your world busy and loud and colorful!

One of my biggest nitpicks in fiction concerns the feeding of babies. Mothers dying during/shortly after childbirth or the baby being separated form the mother shortly after birth is pretty common in fiction. It is/was also common enough in real life, which is why I think a lot of writers/readers don't think too hard about this. however. Historically, the only reason the vast majority of babies survived being separated from their mother was because there was at least one other woman around to breastfeed them. Before modern formula, yes, people did use other substitutes, but they were rarely, if ever, nutritionally sufficient.

Newborns can't eat adult food. They can't really survive on animal milk. If your story takes place in a world before/without formula, a baby separated from its mother is going to either be nursed by someone else, or starve.

It doesn't have to be a huge plot point, but idk at least don't explicitly describe the situation as excluding the possibility of a wetnurse. "The father or the great grandmother or the neighbor man or the older sibling took and raised the baby completely alone in a cave for a year." Nope. That baby is dead I'm sorry. "The baby was kidnapped shortly after birth by a wizard and hidden away in a secret tower" um quick question was the wizard lactating? "The mother refused to see or touch her child after birth so the baby was left to the care of the ailing grandfather" the grandfather who made the necessary arrangements with women in the neighborhood, right? right? OR THAT GREAT OFFENDER "A newborn baby was left on the doorstep and they brought it in and took care of it no issues" What Are You Going to Feed That Baby. Hello?

Like. It's not impossible, but arrangements are going to have to be made. There are some logistics.

Level 1: Characters in a fantastical setting with no clear analogue of any real-world culture or religion celebrate Christmas; the implications of this are never examined

Level 2: Characters in a fantastical setting celebrate a secular, non-denominational mid-winter holiday which just coincidentally involves many of the same rituals and observances as Christmas

Level 3: Characters in a fantastical setting celebrate a mid-winter holiday commemorating an invented folk-hero whose mythos furnishes elaborate alternative explanations for various Christmas observances

Level 4: Characters in a fantastical setting celebrate Christmas because in spite of the setting's history otherwise bearing no resemblance to that of Earth, for some reason Catholicism still exists

Level 5: Whatever C S Lewis was on

I think one obvious way to immediately deepen your worldbuilding is to just not portray groups as being solidly united in their goals or values.

That new civilization you're inventing? Don't make them all completely agree with their government. Don't make them all believe the same things. Don't build a singular culture that is shared by 100% of the population.

This is obvious but a lot of professionally-made fiction does not do it. They have entire species that exist as unitary entities with no internal divisions or factions.

Depressingly, a lot of people think about actual international politics in this way as well.

Thinkin bout space. And magic. And loading screen tips for a game about space magic.

imagine if doorways grew back like scabbed over with fresh drywall and you had to keep carving them back out with a jabsaw to keep the doorway clear etc

Concept: Vampire character that represents strengthening ties to humanity and the natural world instead of dividing them

Vampire gets HEAVILY invested in eco conservation because they *can't* just shrug it off as the next generation's problems

A vampire that goes around eating oil tycoons and clear-cut logging CEOs and climate-denying politicians because their childhood village is a dirt pit now and the animals they saw growing up have become endangered

Immortal guys who anonymously donate huge sums of cash to wildlife preserves that oversee forests they used to hunt in

Fellow who, instead of succumbing to the boredom and waste of infinite time, has become feverishly obsessed with making sure this one specific species of snail will still be around in another hundred years

5000 year old woodsman who can still mimic the calls of extinct birds, who still remembers the mating calls of mammoths and wooly rhinos and wild horses

Ancient vampire who can still vaguely recall a cave somewhere with her whole family's hand prints in it, and not sure of it's precise location, keeps the whole area void of human activity so it doesn't become a tourist attraction

Vampire archeologist who digs up their old friend's remains and has the figure out how to prove, with evidence, how they know exactly who they were and what they looked like

Immortal anthropologist who reconstructs a face from a skull only to realize that they'd met them before a long, long time ago