Jack Vance had a tin ear for proper nouns in alien languages - his approach seems to have involved just putting jumbles of consonants and vowels together. Pnume, Phung, Dirdir, Coad, Az, Braz...they sound a bit like the kind of species and place names an 11-year old invents. But other than that, it's astonishing how much of an interesting vibe there is to his worldbuilding, for want of a better word. These books are each about 150 pages long and the action is typically Vance-paced and lickety-split. One doesn't get the impression he spent a long time plotting them, or thinking about the world of Tschai in a deep and meaningful way.
But nonetheless, it does manage to feel deep regardless. I think this is because of his expert use of what I'm going to christen Glimpsed-at Worldbuilding - a way of referring obliquely to places, races and things that will never come up again in the story but make the world seem very complicated, rich, and lived-in. Take this section, for instance:
Coad was a busy town. Along the crooked streets, in and out of the ale-coloured sunlight, moved men and women of many castes and colours: Yellow Islanders and Black Islanders, Horasin bark-merchants muffled in grey robes; Caucasoids such as Traz from the Aman Steppe; Dirdirmen and Dirdir-men hybrids; dwarfish Sieps from the eastern slopes of the Ojzanalai who played music in the streets; a few flat-faced white men from the far south of Kislovan. The natives, the Tans, were an affable fox-faced people, with wide polished cheek bones, pointed chins, russet or dark brown hair cut in a ledge across the ears and foreheads. Their usual garments were knee-length breeches, embroidered vest, a round black pie-plate hat. Palanquins were numerous, carried by short gnarled men with oddly long noses and stringy black hair: apparently a race to themselves; Reith saw them in no other occupation. Later he learned them to be natives of Grenie at the head of the Dwan Zher.... Once Traz grabbed his elbow and pointed to a pair of thin men in loose black trousers, black capes with tall collars all but enveloping their faces, soft cylindrical black hats with wide brims: caricatures of mystery and intrigue. "Pnumekin!" hissed Traz in something between shock and outrage. "Look at them! They walk among other men without a look aside, and their minds full of strange thinking!"
This is easily caricatured as akin to the Mos Eisley cantina, but the crucial difference between what Vance is doing here and what Lucas was doing in that scene in Star Wars is that here you get those little extra snippets of pseudo information - names, places - that give the reader a sense that there really is an authentic world out there rather than just a lot of extra puppets and costumes in the studio. These are like tiny little amuses-bouches for the imagination: what's a Siep? What are Yellow Islanders? What's the Dwan Zher and why are the natives of Grenie rushing around with palanquins? You hope you'll find out, but at the same time you're almost happier not to, so that you can imagine for yourself.
I also think it's pretty clear that Vance was making this stuff up as he went along - he probably didn't have the answers for any of those questions yet either, until and unless they became significant. As a way of worldbuilding I think that's surprisingly effective: it makes things seem somehow untidy and illogical, which is of course precisely how the real world (and presumably real "worlds" if they indeed exist).
Pulling this off as a DM is not easy, because it places a lot of strain on one's creativity, but also rewarding: eventually, the PCs might want to find out the answers to those questions, and you're going therefore to have to decide for yourself what a Siep is, where the Yellow Islands are, and all the rest of it. But that's going to be fun for you too - which, let's face it, is all that really matters.