Here are two paragraphs I sometimes give my students to compare:
Paragraph 1: "It was a big old barn. There were horses and cows and sheep inside, and a lot of other things lying around, like hay. The barn was really smelly."
Paragraph 2: "The barn was very large. It was very old. It smelled of hay and it smelled of manure. It smelled of the perspiration of tired horses and the wonderful sweet breath of patient cows. It often had a sort of peaceful smell—as though nothing bad could happen ever again in the world. It smelled of grain and of harness dressing and of axle grease and of rubber boots and of new rope. And whenever the cat was given a fish-head to eat, the barn would smell of fish. But mostly it smelled of hay, for there was always hay in the great loft up overhead. And there was always hay being pitched down to the cows and horses and the sheep."
The first paragraph is a simple, rather boring description of a barn that gives us a few general details, but it sounds like every other barn in the world. The second paragraph is E. B. White's description of the barn in Charlotte's Web. Notice how he uses smells to tell us all sorts of specific details about this particular barn--what's in it, who lives there, what the horses and the cows are like, what kind of activities happen there, and most of all, what it feels like to be in this barn. Even if you were standing there with your eyes were closed, he seems to be saying, you would be able to get a picture of this place just by using your nose.
Write a description of a place using only your nose. Well, your nose and a pencil. Can you help someone really feel what it's like to be there by filling your description with as many smells as possible?