- Read, read, read, read, read, read. Everyone always says that because it's true. But don't necessarily read just anything, read various styles of writing and create a basic taxonomy of those stylesthat you can refer to mentally, in a mindset that's more like concentrated practice than just breezy reading. Pay attention to structure, tone, form, use of (or wilful disregard for) grammar, and cadences.
- Learn how to break down basic sentence structure. Know what a gerund phrase and subordinate clause are, or how to spot a sentence splice. You can ignore the "rules" but you need to know them.
- To expand on number 2: Be able to instinctively identify the subject, verb, and object of your sentences. Every sentence has 'em, at least a subject and a verb. This isn't a firm rule, but there's an excellent chance that your sentence's perceived meaning hinges on them, no matter how complicated. And for reference subject, verb and object of the last sentence by the way were "there" "is" and "chance" respectively, not the thing that looks like a sentence and follows the word "that." Now that you know what they are exploit them. Most likely there's a better verb than variations on "to be" such as "is" "was" "has been" and the like.
- Write. But don't just write whatever comes to mind (though you should do that too): write to form. Now that you're being observant of how certain styles are structured and their conventions you can try for yourself. Attempt to mimic the way certain kinds of prose are written.
Here are a few examples of the same thing in various styles picked at random:
"Triangle" - straight news format aka New York Times or AP style
Wilson Phillips, an internet user from Skokie, Illinois, visited the popular online site Quora today in an attempt to learn how to write. In a visit Mr. Phillips described as "disturbing," site contributors were alleged to have committed several acts of hostility, including accusations he was an disgruntled former employee of Myspace, a claim Mr. Phillips denies.
"Time Magazine" - famous backwards construction used in features
The clicks on the keyboard started out even, but soon picked up in speed. As comments were added, tempers flared. A voice rang out. "They should be so lucky as to work for Rupert!" it said, as minutes became hours. Broad daylight gave way to a dim monitor glow, and a grim realization took hold. It was almost midnight, and Wilson's secret was out.
"Gawker" - ie snarky news/blog style
It looks like Wilson won't be getting off this island any time soon. Sources tell us the ex social-ite had a run in with the valley mafia late last night on Quora, which is quickly turning from a minor Mike Arrington masturbatory obsession into a digital mob.
"Gonzo" - Hunter S. Thompson, the master
They're a vile bunch, mean on a good day and as vicious as a badger when cornered. And to them Wilson was prey. A life and reputation torn into meat and bone, the bastard never had a chance. Of course for predators that's the price of a meal, and he wasn't even the first that day.
Heh. The details matter. Ask most people to write the first sentence of a story about a run of the mill news event like a house fire and they'll probably do something like "A house on Main Street burned down today" when in real life those stories usually come at the news sideways. For example: "Broken windows and car alarms were among the unpleasant sights this morning at the site of a residential blaze that claimed three downtown homes".
And so on... ya get the point. And that's just journalism; do the same with modern fiction, magical realism, classic literature, your favorite writers, etc. Once you can separate style from subject you have a set of tools that can evoke a mood. Like a musician practices ear training to identify pitch or major from minor keys you should know the mechanics that underpin a certain feel or tone, and use them, even when you forget you're using any style and just have your own voice.