I wanted to post some links to writing rules, because I think teachers often get this wrong. There seems to be an emphasis when teaching writing to emphasize purplish prose, prose that tries to break out of the norm with extensive use of adjectives, adverbs, and alternative verbs. Unfortunately, this tends to make prose to read like a baroque menagerie instead of something lean and elegant.
Let's begin by reading Elmore Leonard's Rules for Writing.
Then read Laura Miller's A Reader's Advice to Writers.
Both of these writers tend to say the same thing: Keep your writing spare and don't show off. Story matters more than description. Don't try to force style; style should come out of your prose, not be the purpose of your prose.
My favorite rules have to do with dialog. Instead of convulsing with effort to not use the word “said”, to embrace it. The purpose of dialog is to write down what people say, not to elaborate on how people speak. A good writer will get the how across without having to tell us how. So please, no more lines like, he spat, growled, sneered, crooned, or ejaculated. (Please, please, please, avoid that last one.) Keep your prose simple and direct, and let the story tell itself.
Unfortunately a lot of English teachers teacher writing without being writers themselves, which is like teaching a sport without ever having played it. Reading a lot of good prose certainly helps, and this is something most English teachers do well, but how many actually go through the painful process of trying to write good fiction? I'm not trying to be elitist here, but a little experience in that regard goes a long way. Good writing is spare, not fancy.
As teachers, let's try to avoid making our students write parodies of good writing. Let's help them write good, simple, elegant prose. The flourishes and fancy stuff can come later, after they've gotten control of words. Until then, KISS.