Okay, so I've been designing a new story. Making a sale tends to inspire me in that way. I thought I'd share some thoughts.
When I do a linguistic/cultural story I tend to start with five questions (or so)
1. What is the linguistic problem?
This is the toughest one. What is the exact phenomenon that our linguist hero (whether it be his POV or not) is trying to pin down? What is the punch line? Without this, no story can work.
2. Who are the aliens?
Here I'm talking about what kind of animal to base the aliens on. Yes, you can design an alien from scratch, but it puts a huge processing demand on the reader. If the nature of the alien is part of the central point of the story, then by all means go to the trouble of designing their physiology from the ground up. A great example of aliens of this type is the story "Doctor Alien" by Rajnar Vajra, which appeared in the January/February issue of Analog. I loved that story. But because for me the way the aliens speak is the main issue, I don't want to send a lot of my reader's attention toward understanding the physical and physiological nature of the aliens. Sometimes I like to select an animal that fits well with the language phenomenon I'm looking at, like wolves for status language. Other times there isn't a really good parallel between an animal and a language phenomenon, so I can pick something else. But after I pick an alien, I try to look at their diet and behavioral patterns so I can use that information to expand my understanding of how the aliens might live.
3. What is the alien technology level?
This is one of those details that has to be pinned down, of course. I like to try to make their technology real in an atypical way, by considering how the aliens make light, and what kind of objects they would keep in a home, etc. This one has two sub-steps: first designing the objects, and second, figuring out what they mean to the aliens.
4. What is the plot?
Those who know me will laugh at this one, because honestly, the plot comes as number 3 or 4 in the list for me, every time. Once I've got a sequence of events to work with, I continue tuning it throughout writing and rewriting.
5. What is the language?
This is not the same as the language problem - it's the structure of the language, mostly the phonology and morphology. That means the sounds and the way the sounds are put together. I also have to know aspects of the language that relate to the language problem listed above, but this is where I have to figure out how the alien physiology meshes with the sounds they make, what words they might use in the context of the story, how the names and titles work, etc.
These are of course only the entry points. But the nature of these stories is so complex that I can't just sit down and start something; I have to figure out this kind of stuff first. I know I'm getting close to sitting down when I start hearing names and alien phrases in my head, and seeing a scene where two entities are talking to one another.