One of the things that my worldbuilding workshop has got me thinking about is defining objects. I think objects generally fall into a sort of scale that ranges from the ultra-specific to the generic. A specific object is something where the mention of its name brings to mind only one thing. "Mr. Spock's ears," for example. A generic object is one that comes in so many different types that simple mention of its name brings up only a prototype image. "House," "wall," "window," and "dog" are examples of this category. In between is a large range of different kinds of objects. The word "pulley" is pretty specific; if we want additional information it will probably be what the pulley is being used for, or what it's made of. The word "fan" is in the middle - heavily informed by context, but depending on whether it's included in a description of a Japanese woman, or of kids in a house without air conditioning in modern-day California, it need not necessarily be explained.
When I talk about explaining a word, that doesn't mean explaining it in depth. It only means making sure its meaning is specific rather than general. A "brick wall" is very different from a "steel wall," which is very different from a "stone wall" (and fortunately all of these are very different from "a wall"). If you want to get more specific, you can say "a crumbling brick wall" or "a used-brick wall." If you want a Japanese wall with a foundation of granite blocks the size of cars and an upper storey of white plaster topped with gray tiles, you have to go so far as to say that, because you can't rely on all your readers to pull that image up from context.
Explanations like these can help to adjust the knowledge sets you establish in your world. A reader entering an unknown world for the first time is going to be looking for cues to the world, and hoping for enough specificity to establish a unique world sense. When I introduce my Varin world, I like to specify that this is a world where wood is scarce, so I'll often describe a room and specify that the bed frame is made of brass, or that though there's a heavy mirror framed in wrought silver, the most expensive-looking object in the room (from the character's point of view, of course) is a wooden cabinet in the corner.
Gradually, as you enter your world further and further with the reader, the details you provide will build up into an overall impression of this world in all its uniqueness. And if you've done your job well, you may discover that by the time you're halfway through, you've actually redefined common words like "table" or "wall," so that the objects that your reader imagines are generated world-appropriately. You will have trained your reader to know that tables aren't made of wood, or to know that they must expect walls to be made of light, or to know that it means something special when this character uses the word "friend," because it wasn't a natural concept within his world.
In effect, world details aren't just details. They're not just stuff sitting in the room because otherwise the room would be empty. They are tools by which you draw your reader so far into your world that they judge the objects they read about as though they lived there.
As a reader, that's what I always loved - feeling like I was part of that world on paper. And as a writer, I can hardly imagine anything more exciting than being able to bring others into my world with me.
It's something to think about.