Before China Miéville wrote fiction, he wrote a PhD dissertation on Marxism and international law. He studied at the London School of Economics and Harvard. He ran for parliament on the Socialist Alliance ticket. He was, by every measure, a political theorist first and a novelist second.
Then he published Perdido Street Station in 2000 and built New Crobuzon, a city that runs on steam and thaumaturgy, where the infrastructure itself is an argument about who has power and who doesn't. The novel didn't borrow steampunk's visual language to tell a political story. The technology was the politics. Every boiler, every construct, every arcane engine existed because someone with capital needed it to exist and someone without capital got burned building it.
What's easy to miss, if you only read the novel, is that Miéville didn't arrive at this through worldbuilding exercises or genre conventions. He arrived at it through theory. Years of reading about how systems produce and distribute power, and then he asked himself what that would look like if the systems ran on steam. I'm not sure any other steampunk writer has come at the genre from quite that direction, and I think it's why the city feels so structurally solid. It wasn't designed. It was argued into existence.
The technology tells you who has power and who doesn't
Most steampunk novels describe their technology. The good ones interrogate it. There's a difference between a brass automaton that looks interesting on a page and a brass automaton that exists because a factory owner figured out it was cheaper than paying a human being. The first one is set dressing. The second one is a story.
Miéville understood this because he'd spent years thinking about how real economies work. In New Crobuzon, the Construct Council is a pile of discarded machines that have become sentient through sheer accumulation, a kind of consciousness emerging from industrial waste. That's not just a cool image. It's an argument about what happens when you throw away enough of something: it starts thinking for itself. The throwaway gains agency.
If you're building a steampunk world, the question worth asking isn't what does this machine do. It's who paid for it, who operates it, and what happens to the person who can't afford one. The answers to those three questions will generate more plot than any amount of brass filigree.
Constrained settings force the most inventive worldbuilding
Josiah Bancroft's Senlin Ascends takes place almost entirely inside a tower. The Tower of Babel, to be specific, reimagined as a massive structure where each level is a different society with different customs, different technologies, and different rules for how people get in and out. Senlin, a schoolteacher on his honeymoon, gets separated from his wife and has to climb.
The constraint is what makes it brilliant. Because Bancroft can't sprawl outward into continents and kingdoms, he has to drill down. Each ringdom (his word for a level) is a complete world in miniature: its own economy, its own architecture, its own version of steam-era technology adapted to a specific purpose. One level is a theater that never stops performing. Another is a spa that drugs its visitors into complacency. The steampunk elements aren't uniform. They shift with every floor, shaped by whoever controls that particular slice of the tower.
This is a useful principle for any steampunk writer, even if you're working on a much larger canvas. Limit the space. Give the technology a reason to vary from place to place. A city where every district uses the same machines is a city that hasn't been thought through yet, because real technology is always local, always adapted, always a little different depending on who needed it and what they could afford.