Worldbuilding 101: The Three Zones

So you feel ready to build your world but you don't know where to start. Suddenly the enormity of your task dawns on you and you panic! Do I have to script out every town and city, their populace, points of interest, and ruling bodies? Do I need to know how the toilets flush? And so you searched online for assistance. So did I.

Sadly I gleaned very little about a process for actually building a world. It all felt like that old cartoon joke:

I've made a few observations on the subject that might assist you in this endeavor. First, we will zoom out to view your entire blank world. What is your world? It's the playground for your players. But we need to know how they want to play. How do we find out? Well, there are typically three playground zones in any setting. They are:

1. Civilization: This zone is all about the inner cities, the core worlds, mega-city 1. If your players want adventures in the city, they are telling you they want a game about intrigue. The villain's are primarily other people. The heroes must navigate their way through political pressure, corruption, all while making the right allies to help keep them alive. Cyberpunk is exclusively a civilization game. 
2. The Fringe: The fringe is where civilization has a tentative hold over the wilderness. It's a popular starting location as it offers both intrigue and exploration storylines. It's also a quick hop back into a city if the heroes want, or into the wilderness. Fringe stories involve societal breakdowns like raiders, rising warlords, and corruption but also include stories about natural disasters, plagues, pestilence, rampaging creatures, and forbidden things lurking in the shadows. Players will often be hired to deal with local problems since on the fringe, there aren't a lot of peace-keepers. Almost the entirety of the original Star Wars trilogy occurred in the fringe of the Empire. We only ever saw one civilized world... briefly, Alderaan.
3. The Wild: If your players choose to play in the wild, they are telling you they want survival to be important. In the wild, there is no resupply or comfy taverns. In the wild, anything strange can and should happen. The players are out here to explore. The locations should be awe inspiring. The threats should be unique and terrifying. This is the home of lost civilizations, ruined tombs, and undiscovered countries. Give it to them.

D&D tends to place its lost tombs conveniently in the fringe so that adventurers can investigate a sunken temple at noon and be back at the pub by nightfall for fried chicken. Well the fringe is a good place for it but might I suggest treating the search for the sunken temple as a transition between the fringe and the wild? You'll get more adventures out of it and survival without support will ratchet up the suspense.

So now that you know the three zones, what do you do with them?

If the players choose to play in civilization, then you know you need to pour your efforts into a city. That's just ONE city. Where do I put it on the map? It doesn't matter. There ought to be plenty of adventure there and it doesn't sound like your players are in the mood for cross-country travel.

If the player's choose the fringe, then you know you need a town. Your players may not like the town you have made but they won't know that until after the first adventure. Once you have an idea for a town, come up with three things that are troubling the town: Frequent orc raids, a mysterious blight on the crops, and a band of thieves are harassing the townsfolk. Your players will choose to tackle one of these issues, and if they hate the town by the end of the adventure they can go to a different town. In which case make a town more to their liking and come up with three things that are troubling the new town: Well those orc raiders are striking here as well, children are suffering from a strange "sleeping sickness", and there's rumor of a sunken temple in the nearby swamp. Build the towns as they are needed.

What if the heroes choose the wild? Then build an amazing location that holds a terrible secret, don't forget the keeper(s) of that secret. Also focus on how the heroes are able to survive the wilderness trek. What problems might they face? What random creatures might they encounter? Each adventure the heroes should: experience an amazing locale, fight something they've never encountered before, and learn a secret that the forgotten place holds. Here's an example: My heroes are trekking in the wilderness, survivors of a shipwreck, cast away on an unexplored shore. They strive to survive the wilderness when they come across an inland grotto decorated with the remains of torn-apart ships. What are they doing this far inland? The water in the grotto links to the ocean and the grotto is the lair of a kraken! The same kraken that destroyed the heroes' ship! That's not all. A local tribe of beast-men worship the kraken and view the pillaged vessels as gifts. As far as they are concerned, the heroes have violated their holy ground.