First rule of Worldbuilding: Don’t make everything all at once.

It’s hard to resist sometimes, but if you focus too much on the large-scale, you will soon feel stretched too far. Instead, try working in smaller increments. Go to a particular area in your world. What is it like? What has happened in the last 100 years? The last 1,000 years? If you do it this way, not only is it more manageable, but it also allows you to make each individual area more interesting and unique.

Second rule of Worldbuilding: Remember to make a timeline!

Having a set timeline of your world, or even just for a city or country, can make life so much easier. It can also answer questions. For example: “Why is ______ city so poor, with almost no military protection?” Answer: “Because a decade ago, a plague swept over it, killing many of the towns people, including merchants and guards.”

Third and final(for my list) rule of Worldbuilding: Nothing is set in stone- until it is.

Let mw explain. Certain parts of your world, how it works, and how it happens are set in stone- they are vital to running the world as a whole. But as a DM with players, you must let their actions also control the world. A world seems easier to run if all aspects are made already, sure. But it makes the players feel as if their actions have no impact. For example if the party defeats a corrupt king, who would take his place afterwards? If the party removes a curse, letting the drought over a land vanish, what would happen? Let the players mould the present in your world- it should not be immutable. (If time travel is involved, then try adding consequences to it as well.)

I hope my three rules help you out! Good luck, worldbuilder!