Trying to run a DND campaign for the first time but I don’t know anything about map making, geography, or geology. I want the physical features of the land to mostly make sense from a geological perspective and then conform the borders of my city-states and empire to their natural geographic constraints. How do I even begin with this?
Make continents, imagine where plates would be and put mountains there, imagine rough elevations of land in general, start rivers on the mountains/other raised bits in amounts proportional to how close the nearest large body of water is and start them on that side, rivers collect they don’t branch until a delta maybe, rivers follow elevation — straight when rapid changes and meandering in curves on flats, rivers run to the sea optionally making lakes or swamps in flat areas.
Major cities control important locations (rivers, harbours, mountain passes etc) and are on water with access to fresh water and farmland nearby. Farmland needs water, settlements generally need running water to be permanent.
Also have fun. Put a blasted mesa that spews posionous miasma because a god died there. Make a chasm that is so deep nobody has ever plumbed its depths and liquid shadow collects in the bottom, add a migratory forest that strips the topsoil of nutrients as it passes through.