I just read an article called It is known -- Game of Thrones, the Orient, and Conventional Wisdom. It's a great explanation of otherness in fantasy, and the treatment of other races -- particularly how, in Game of Thrones, though he gets a lot of things right, George R. R. Martin treats the non-Westerosi cultures as far more homogeneous than the cultures of Westeros, and fails to construct a mind/culture separation in non-Westerosi characters.
Consider the the rival powers in Westeros. The Starks are fatalistic, duty-bound, honorable but kind of unsophisticated. The Lannisters are appetite-driven plutocrats. The Baratheons were markedly varied, but the surviving one is driven and joyless, [...]
Now, consider the rival powers among the Dothraki. Was it Khal Jommo’s khalasar that valued chivalry? Were Khal Ogo’s people the least trustworthy? Did Khal Drogo’s have a unique worldview shaped from their long tradition of cultural exchange with the Free Cities? Or are all the khalasars exactly freaking the same, because that’s how it works when you’re an oriental other in speculative fiction?
It's a very interesting read, and I think you should go check it out.
While I was reading it, I was mostly thinking about my own work. Right now I'm working on a short story, tentatively called "The Rain Castle," in a fairly traditional fantasy-style setting. (Embarrassed confession: I'm building off the groundwork I built for a D&D campaign to make this setting, so the fundamental seeds are quite deeply buried in the elves-and-goblins tradition of fantasy.)
It's inevitable in this kind of fantasy that I'm going to have more than one race, and I'm trying to do better than the actually-biologically-different standard and create something more fundamentally cultural and social. The general sketch of my idea is that magic = greater variation, but also greater possible variation without speciation.
In order to work through the first draft, I've resigned myself to the fact that it's going to be racist. I'm a white person writing in America with no experience actually being in a non-Anglo-cultured environment, never mind having anything resembling real experience with other cultures. I'm trying my best, but I have to accept that I'm going to get things pretty badly wrong my first draft through.
This article has given me a lot to think about, when it comes to figuring out what I'm going to need to fix. Keeping an eye out for self/culture conflation should help. And when it comes time to developing the different nations or nationlike groups in the broader map (something I'm doing sort of haphazardly as I go along) I'm going to work hard to make sure that, even if from the perspective of the most western-ish culture they seem all the same, no larger culture lacks meaningful diversity within its groups.
Here's that link again, and if anybody else knows any good resources on non-racist worldbuilding, please send them my way.