I've always told my students in prose writing classes (composition, fiction, or nonfiction) that if they really want to learn how to write, they should take a poetry writing class. The focus of poetry is language itself, all its intricacies and trills and hauntings. Poets have to focus on a single word's impact in a line. They need to know a word's multiple meanings and associations, often even a word's etymology.
In a fiction or nonfiction writing class, there tends to be so much focus on storytelling or form and composition, that the basics about the language are brushed over, if they're touched on at all. For these and other reasons, often, one of the first things I teach in a writing class is metrics.
Part of the reason that I start with metrics is that it can be particularly difficult to figure out. My feeling as to why this is the case is that most of the people I've taught over the years were native English speakers. I think this is the same reason why grammar can be so difficult for many to figure out. When you speak a language as a native speaker, you simply speak it, and you speak expertly, and you don't think about it. So breaking down that native language into its distinct syllables and trying to figure out where the accents in the language fall can be daunting.
I steal this line from an Austin Powers movie (I don't remember which one this is from and can't seem to find a clip of it): "You put the wrong emPHASis on the wrong sylLABle." And that's the first trick to learning metrics. Try pronouncing multisyllabic words incorrectly. If I misplace the emphasis in my own first name, the pronunciation makes it sound French or something: JamIE, instead of JAMie. I often have students go around the room, mispronouncing their own names, which not only shows them where emphasis falls in their names, but has the added bonus of garnering a number of giggles and keeping people engaged.
After this little exercise, I introduce scansion, the method by which a reader scans language for its metrical patterns. I teach them about the breve (˘, or, alternatively a simple x works) and the ictus (/). And I'll use this to scan my name for he class as well: Jámĭe.
The good thing about using my name in this way is that this gives me the opportunity to introduce a couple new concepts: metrical feet. Since my name is disyllabic, I can point out that my name itself is a trochee, and if I mispronounce it (Jǎmíe) I can scan it so that it becomes an iamb.
Usually at this point it's worth it to bring about a few more giggles, so I take the opportunity to explain that metrics and scansion is not and never could be an exact science, simply because there are so many Englishes. Certain regional dialects will pronounce things differently. Thus, since I'm from California I tend to pronounce a word like "guitar" like this: (add extremely exaggerated surfer dude accent) gŭitár. And I come up with a goofy sentence like "If I play my gŭitár too loud, someone might call the pǒlíce." But then I switch things up, saying that I've lived in the South for the past 15 years, so now I play my (add extremely exaggerated Southern accent) "gúitǎr" and if I'm too loud someone's gonna call the "pólĭce." So, this goes to show that words are not always scanned the same ways all the time.
And what this naturally leads to next is explaining what the effect of understanding these two simple metrical patterns can have: altering the way a reader might read your sentences. A sentence that has a largely iambic metrical pattern we can say has a rising meter. Sentences with such a pattern tend to read quickly with a soft, lilting kind of rhythm. Go back to my name again and mispronounce it so that the emphasis falls on the second syllable. Now say my name five times in a row (for kicks, and because it might help to illustrate, maybe pronounce my name this way with a French accent): Jǎmíe Jǎmíe Jǎmíe Jǎmíe Jǎmíe. Now do the same thing, but pronounce my name correctly: Jámĭe Jámĭe Jámĭe Jámĭe Jámĭe. You should be able to hear that when you pronounce my name trochaically, it comes off the tongue much slower and more stilted. Incidentally, we just composed two lines of metrical feet: the first of iambic pentameter and the latter of trochaic pentameter. However, I do tell students that knowing metrical feet in this way isn't all that important for writing prose.
What is important, though, is understanding that you can use metrical feet to compose sentences that affect the reader's reading rhythm in the way you want them to experience your sentences.
Take the following sentences as examples:
"He stepped into the ring against his opponent, a hulking mass of chiseled flesh, his face knotted and scarred from previous battle. The bell rang. The fighters danced and jabbed. A fist broke through barred arms, touched the nose. All guard went down. He charged, swinging. When the ref separated the men, the crowd roared, the blood stained the tarpaulin, the ref's voice chanting underneath the cheers: one, two, three . . ."
Notice how the sentences' rhythms change with the action. When the first fighter enters the boxing ring, the rhythm is almost iambic and things seem to move swiftly, that is, until he sees his opponent, "a hulking mass." the trochee of "hulking" followed by the single stressed syllable of "mass" slows the reader down, probably just like time might seem to slow down for that fighter as he gets ready to fight this scarred warrior. Similarly, the rhythm slows when the fighting gets more intense: "A fist broke through barred arms, touched the nose. All guard went down. He charged, swinging." It's almost how, if you've ever been in an intense situation, your memory of it makes it feel like events transpired a lot more slowly than they actually did. So it makes sense that the rhythm starts moving more quickly in the next sentence, but slows upon the final single stressed syllables of the ref counting for the knockout.
These tricks to learning about metrics and learning how to use them in your writing--and they literally are tricks--will serve your sentences and your reader's ear and help make your writing stand out from others', something you surely want when submitting your work for publication.