1. Keep It Short and Simple
Do your readers a favor: write in short sentences and use simple words. We are wrong to believe that big words and long sentences indicate intelligence. A concise letter or report is more effective; it saves reading and writing time. Your main points won't fade into a background of unnecessary words.
Read sentences out loud to check their length. If you run out of breath, they're too long. Better yet, read your writing to someone else. If your listener forgets the beginning before you finish, you need to break your thoughts into two or more sentences. Eliminate extra words whenever you can.
2. Be Specific and Avoid Generalizations
Use specific, concrete words instead of vague generalizations. Don't make your readers guess about the meaning of your message; it wastes their time as well as yours. For example, which of the following sentences conveys the most information? "Please get back to us as soon as possible regarding your return," or: "To complete your 1040 form before the deadline, we must hear from you before April 1."
3. Use the Active Voice
Avoid dead, dull-sounding writing by sticking to the active voice, in which the subject is the doer of the action. "The client filed the Schedule C" is an active sentence. "The Schedule C was filed by the client" is passive.
The passive voice makes sentences longer and more impersonal. The active voice sounds alive, personal and demanding. For example, "Your prompt attention to this letter will be appreciated" is considerably crisper in the active voice: "Please attend to this matter promptly."
4. Use Parallel Structure
Organize your sentences with parallel structure. Your writing will be much smoother and clearer if you put related ideas in the same tense and form. For example, "I came, I saw, I conquered," sounds a lot snappier than "I arrived, then having seen, I proceeded to conquer."
When you're writing a letter to a prospective client, it's awkward to write: "Our firm offers a range of services: preparing financial statements, help your plan your strategies, train you in computers and provide business consulting."
5. Organize your writing
Always create an outline before starting to write. Even if you only jot down five or six words, it will save you writing time and remind you of where you're headed. More importantly, your readers won't get lost in a poorly organized document that causes them to ignore or misunderstand your message.
Get to the point immediately. Busy readers should be able to get your message in the first two or three sentences of your document. Start with the conclusion or call to action, then list your primary arguments. Provide the back-up or discussion material at the end for anyone who has time to read that far.
6. Watch Your Tone
The way you "talk" in writing gives your readers a mental picture of your personality. Write informally, as a friendly, concerned professional. If you sound too formal or long-winded, that's how your readers will envision you.
Use positive words and expressions instead of negative ones. If you want to motivate your readers, positive languages works best. Avoid writing "you claim," which implies: "you say so, but I don't believe you." Words such as "failed to," "neglected to" or "lack of" can sound accusatory. For example, instead of: "This notice is regarding your failure to remit payment on our invoice," you might use: "Did you receive our invoice of Sept. 12, 1995?"
7. Edit for Grammar, Punctuation, and Spelling
Spelling and grammatical errors not only convey a sloppy image, but also can cost you business. For example, a hyphen in the wrong place can inadvertently offend your readers: "we are always happy to serve small-business owners," is different than: "We are always happy to serve small business-owners."
Always let someone else edit your writing. Although most word processors have a spell check function that can catch some errors, none of them will catch words that are spelled correctly, but used incorrectly in a sentence. There's no substitute for the human eye - especially the fresh eye of a person who hasn't been looking at the document over and over.
A number of excellent handbooks review common grammatical errors and discuss how to fix them. One of the best is William Strunk, Jr. and E.B. White's classic Elements of Style. It's short, focused, and entertaining.
Source: Oregon State University English Language Institute