I hate naming stuff... I always want the names to be significant/mean something, but don't want them to be recognizable to the players, which probably undermines the entire effort.

Usually what I'll do is name everything in English, and then peruse online dictionaries of more obscure languages that thematically match the setting. I'm usually satisfied with any language that isn't English, Spanish, French, German, Italian, or any language that a player at the table knows.

I did this with pretty good success for an arabic-themed city and was pleased with the results. Eventually I forgot what most of the words meant, but just knowing that they meant something made them seem more realistic to me.

I have an even harder time naming characters, but that's not related to mapping efforts.