明瞭でわかりやすい英文を書く際に，17章 Revising Style は非常に参考になりそうなので，英文のまま引用します．本文では例があげられ詳しく説明されています．少しでも興味があればぜひ原書をご覧ください．
17.2 THE FIRST TWO PRINCIPLES OF CLEAR WRITING17.2.1 Distinguishing impressions from Their Causes
For that, you need a way to think about sentences that connects an impression like confusing to what it is in the sentence, on the page that confuses you.
The principles focus on only two parts of a sentence: the first six or seven words and the last four or five. Get those words straight, and the rest of the sentence will (usually) take care of itself.
17.2.2Subjects and Characters
Readers will judge your sentences to be clear and readable to the degree that you make their subjects name the main characters in your story.
17.2.3 Verbs, Nouns, Actions
- Express crucial actions in verbs.
- Make your central characters the subjects of those verbs; keep those subjects short, concrete, and specific.
17.2.4 Diagnosis and Revision
- Underline the first six or seven words of every clause, whether main or subordinate.
- Perform two tests:
- Are the underlined subjects concrete characters, not abstractions?
- Do the underlined verbs name specific actions, not generalness like have, make, do, be, and so on?
If the sentence fails either test, you should probably revise.
- Find the characters you want to tell a story about. If you can't, invent them.
- Find what those characters are doing. If their actions are in nouns, change them into verbs.
- Create clauses with your main characters as subjects and their actions as verbs.
17.3 A THIRD PRINCIPLE: OLD BEFORE NEW
Readers follow a story most easily if they can begin each sentence with a character or idea that is familiar to them, either because it was already mentioned or because it comes from the context.
- Underline the first six or seven words of every sentence.
- Have you underlined words that your readers will find familiar and easy to understand (usually words used before)?
- If not, revise.
- Make the first six or seven words refer to familiar information, usually something you have mentioned before (typically your main characters).
- Put at the ends of sentences information that your readers will find unpredictable or complex and therefore harder to understand.
17.4 CHOOSING BETWEEN ACTIVE AND PASSIVE
Rather than worry about active and passive, ask a simpler question: Do your sentences begin with familiar information, preferably a main character? If you put familiar characters in your subjects, you will use the active and passive properly.
17.5 A FINAL PRINCIPLE: COMPLEXITY LAST17.5.1 Introducing Technical Terms
When you introduce technical terms new to your readers, construct your sentences so that those terms appear in the last few words.
17.5.2 Introducing Complex Information
Put complex bundles of ideas that require long phrases or clauses at the end of a sentence, never at the beginning.
17.5.3 Introducing What Follows
When you start a paragraph, put at the end of its first or second sentence the key terms that appear in the rest of the paragraph.