Sometimes we leave out place names to create a more diffuse sense of place and to help people feel immersed, as though the location belongs to them. Sometimes we use specific places. Sometimes we pick a real-world region, but not a specific city. A specific name can send someone looking on a map. Sometimes we can choose names, like Springfield, that come across as generic, or recombine parts of known place names to create names like Midwich, plausible but not anchored.
If you are thinking of a place name, do some research and figure out where it may have appeared before.
Morphology, the study of parts of words, can be very helpful for place names. Suffixes like -burg and -ville are called morphemes, and can be very useful. You can also create your own suffixes to indicate place.
In Britain, a lot of place names have specific meaning in context. The same is true for Native American Indian names for places, which are often linked to local landmarks and other features of place. The English re-naming of locations created a dissociation between the land and its place names by overlaying an imported context.
Uniformity is to be avoided, because it gives a sense of perfect newness, or of monocultural imposition. However, linguistic consistency is important if you are using a conlang.
When it comes to geography, it's important to consider issues like climate and biomes. Research is critical for developing this aspect of your story. Geographical features like mountains can be good for adventure, but they should make sense within a larger system. If you have a mountain range and one side of it is wet and the other dry, it's good to know why that is the case. Consider your planet's rotation, and consider placing your story in the southern hemisphere (because the fact that we have more land in the northern hemisphere is just coincidence).
Brian noted that before the Renaissance, the placement of north vs. south on the top/bottom of maps was not standardized, and you often saw other approaches. (And different projections!)
If you place your story on a different planet, or in a different place on our planet, consider how that might change the night sky. On our planet, different stars are visible, and they move differently, depending on whether you are in the northern or southern hemisphere, or near the equator. On other planets, stars could potentially vary in brightness, concentration, etc.
Thanks to all who attended!