If you want readers to see, and act on, your messages, use the old rule - AIDA!
We older promoters know that the acronym, AIDA, has been around for a long time. It stands for 1) Attract attention, 2) Create Interest, 3) Arouse desire, and 4) Move to action!
If you want results, especially in your writing, follow that rule! Why? Well, your message may never be read if it isn't first noticed; so, you must attract attention. How do you attract attention with your writing? Aside from using some weird graphic devices (don't print on orange paper), you might use a question, a quote or a brief story.
Suppose you're looking for a job and you've written a cover letter; use a question in the first sentence to involve the reader. If you are writing to Microsoft, ask the reader, probably a person in the HR department, this question, "What kind of employee does Microsoft want?" Then, after you have that reader's attention, answer the question. "Microsoft wants motivated, experienced, intelligent...." The next thing you will do, of course, is show how you meet these qualifications.
You can pose just about any question to attract the reader. Questions work because they require participation, and that's what you want! Stories do the same thing; they involve the reader. But, not all stories are created the equally. You will need an appropriate and interesting story - and it must be brief, as little as two sentences at the beginning of your letter, say a cover letter to Microsoft. What brief story might you tell then?
Suppose you grew up in India, you might say, "In my small town near Bangalore, the mayor had the only computer and I sneaked into his office to use it every night. He knew I did, but he also knew of my passion for technology." That story says some things about you that a list of experiences and course work can never say.
Quotes can do the same. Instead of enclosing a list of references, why not use a quote from one of them to begin your cover letter? For instance, "I taught Babalu and have never seen a more passionate, dedicated and intelligent person in my 36 years at CMU. I wish I could hire him!" Or, if you are applying to Microsoft, use a Bill Gates quote, about anything, as long as it relates in some way to you and your talents. In so doing, you will borrow Bill's credibility! Or quote Barack Obama, or Mahatma Gandhi, or another famous person.
After you have the reader's attention, you must sustain it. You must keep her interest and lead her to desire, that is, the desire, in the case of a job inquiry, to know more about you. If you are selling yourself, you must write in such a way that leads the reader to want to see you or talk to you. That's the Action!
What causes this action? First, you have been noticed! Second (and third), you have been interesting and have created a desire in the reader to know more about you. You have moved the reader to pick up the phone and call you. You have used the old rule - AIDA!