We can hardly improve on Joathan Swift's formulation of style: "proper words in proper places." That focuses on the right level of detail, but in begs questions of propriety. What are proper words? And how do you know where their proper places are?
In judging words and their placement, remember that the character of the writer determines the character of the prose. Even when the subject is as alien from everyday life as the Rule in Shelley's Case, style reveals self as surely as anything else. What you say and how you say it reflects your mental habits and your personality. In trying to write your best, you may strive to proportion one part to another and to the whole, to accent what matters most, to cut out what is useless, and to keep an appropriate tone throughout. But even with these goals in mind, different writers -however skilled- will aproach a topic differently, often quite differently.
Style embodies the message, delivers it for circulation. When style suffers -because of poor organization, sloppy paragraphing, clumsy rhythms, thoughtless jangles, or other befogging lapses- the content also suffers. When style is good, the content benefits.
Though all lawyers pay lip service to the importance of good legal writing, few seem to appreciate the capacity of style to influence results. Listen to Lord Denning, probably the greatest of Britain's judicial stylists:
[Y]ou must cultivate a style [that] commands attention. No matter how sound your reasoning, if it is presented in a dull and turgid setting, your hearers -or your readers- will turn aside. They will not stop t listen. They will flick over the pages. But if it is presented in a lively and attractive setting, they will sit up and take notice. They will listen as if spellbound. They will read you with engrossment.
So convinced was Lord Denning of the importance of style that he attributed the British role in winning World War II as much to Winston Churchill's manner of speaking and writing as to Churchill's strategy of intelligence.
For the sake of lesser battles, you need guidance to develop an effective legal style. As used here, the phrase legal style refers generally to expository prose about legal subject, whether in the form of persuasion, narration, description, or analysis. Most forms of legal writing fall within those realms: judicial opinions, advocacy, scholarly commentary, opinion letters, and other writing in and about law. Legal drafting -for instance, of legislation, rules and contracts- requires separate treatment and has received it in some excellent works.
The chief aim of style is clarity. But achieving clarity is only the first step; much remains -brevity, for example, and accuracy. Variety, elegance, imagination, force, and wit can make your prose interesting as well as clear. Often you must do more than simply communicate; you must persuade or even delight.
Don't confuse the negative with the positive virtues of writing: avoiding grammatical and rhetorical gaffes won't make you an exemplary stylist. Despite what some writing texts might have you believe, there are no real formulas for a good prose style. Removing needless passive-voice verbs, keeping sentences short, and using "action" verbs usually improve a piece of writing, but they still may not result in a good style.
Everything hangs on context and purpose. We value simplicity, but writing as simply as possible does not always mean writing simply. Complicated language occasionally proves unavoidable. Take the legislative jungle that is in the tax code: "It can never be made simple, but we can try to avoid making it needlessly complex." We can try to say it in plain language.
But what is "plan language"? I define it as the idiomatic and grammatical use of language that most effectively presents ideas to the reader. By that definition, plain language may be, in some sense, unplain. Who would call Immanuel Kant's categorigal imperative plain, despite the seeming simplicity of the words? "Act as if the maxim on which you act were to become, through your will, a universal law." On the other hand, who would volunteer to simplify it?
Still, most of us aren't framing Kantian thoughts. We should stick to a plain approach. Our age prefers it.
Gardner, Bryan A., Gardner on Language and Writing, 1st ed., pp. 39-40