The genres I have presented in my previous articles are only a handful of the genres a Dungeon Master might develop for his Tech-based campaign world. Using the tools presented, a Dungeon Master should have little trouble devising a fantastical world from their own imaginations. Perhaps you envision a world in which inventors can biologically alter their own forms. Or perhaps a world where people use hovercars to travel between cities in the clouds. All of these worlds and more are available to you.
Another method to create a campaign world tailored to your aesthetics is to take elements from some of the genres mentioned above. After all, the Coltian and Wattian genres occurred contemporaneously in the real world, and they could in yours. Alternately, you could combine Geberian alchemy with Teslan electromagnetism, to create a world powered by alchemical zeppelins that deliver electricity to the population below through dramatic bolts of lightning.
Here are some guidelines for developing a world with fantastic technology:
First, envision how the world looks. What sort of architecture does it have? Are buildings made of stone, brick, metal, glass, plastic, or walls of force? What clothing do people wear? How do they travel?
Second, how is society organized? Is it relatively egalitarian, or does a small minority of plutocrats live in luxury while the vast majority of the population lives in squalor? Are the populations scattered as points of light in a dark and dangerous world or is the world developed to the point where civilization encroaches on the last few wild places in the world?
Third, what dangers threaten this world? Do monsters rampage in the wilderness? Are devils or elementals from other planes invading the lands? Or is the main threat other sentient creatures, shadowy conspiracies, and sinister governments and organizations? What tools do these villains have at their disposal? Do the illithids wield ray guns? Do the gnolls ride motorcycles through the badlands?
Fourth, what tools should be available to the heroes who will confront these threats? Should they have access to guns? How much has magic altered the world?
Fifth, but most importantly, does this feel like a world your players will enjoy? Will they be able to immerse themselves in the world? Is it too alien? Does it feel like a world that could have developed? Does it provide opportunities to create intriguing player characters with compelling stories?