How do you make a fantasy world different? One way is through the names that you give the animals, plants, food, clothes, musical instruments, any and every thing in your world. When well-chosen, these names can paint a vivid, distinctive picture of another world. When they’re poorly chosen, though, they’re like curly squiggles in a Mondrian painting – they call attention to themselves and don’t enhance the rest of the work.
1. Don’t sacrifice clarity to exotica.
I once read a novel where the heroine had “whistleflower-blue eyes”. Each time I came across that description, I would wonder what shade of blue that was supposed to be, and whether the flowers actually whistled, or were perhaps shaped like whistles. In other words, the description didn’t work either to give me a vivid picture of the heroine or to flesh out the world.
If it ever comes down to choosing between the simple mundane description and the overly elaborate one, the simple description is often going to be the better one. You don’t want the readers to stop, jolted out of the story, as they wonder whether “blackberry brandy eyes” are the same as “brown eyes”. It’s not worth it. If you really need a reader to know that there are such things as whistleflowers, have them wolf-whistle when the heroine walks past. Or maybe the hero could pick a bunch of them and tell her that they’re so dark a blue they’re like ink, but her eyes are darker. Hopefully she takes lapses into soppiness as a sign of love.
2. Don’t call a rabbit a smeerp.
The novel I just completed featured zebras, but I felt I had to call them something different. I’d read the term "zorse" in another fantasy novel, so I started referring to zebras as "stripes".
My critiquer read the first chapter and said, "If this is a zebra, why don't you just call it a zebra?" And he was right. Zebras are exotic enough already; there was no need to give them different names, especially names of the smeerp variety. I first read the rule on this site, which contains plenty of other examples of what not to do when writing.
3. Beware of Star Trek syndrome.
This is where every mundane noun gets the facelift of a adjectival place name, so you have Romulan ale, Tarkalian tea and so on. In the Star Trek universe, not only did this get repetitive, but it didn’t convey much information. I watched a lot of Star Trek, but I still don’t know the difference between Tarkalian tea and Lipton. In contrast, in the Song of Ice and Fire novels, George R. R. Martin makes the difference between Valyrian steel and regular steel very clear, so I can see why people value Valyrian steel. A little of this goes a long way, especially when Star Trek has boldly gone there before.
4. Sometimes the familiar can be strange as well.
Tanith Lee is a master of this effect, using the simple and ordinary in ways that are not at all simple and ordinary. Lee makes throwaway references to clockwork cats, marigolds preserved in ice for a dinner party and oranges which release birds when broken open. Martin is good at this too; one of the Song of Ice and Fire novels mentions “pitted olives stuffed with maggots”. Not as pretty, but certainly unusual. There’s no need to make up words – saying that the heroine picks a bunch of Cladiel flowers won’t be as vivid as her picking a bunch of dragonsbreath, or scarlet showers, or butterfly traps. Common words used in uncommon combinations can work very well.
Use as much imagination as the story needs, but don't use less.