This is another one of those "legwork" things, but fortunately these days it doesn’t require any walking around: usually a simple telephone call or a "visit" to the company web site is all you need.
When in doubt, just ask! Call up the company and ask a secretary or receptionist. Talk to a few people -- maybe even speak to the person you plan to address (that will give you a better sense of his or her style and will provide a good introduction to your letter). Just ask, and be nice about it. Who would handle the sort of project you have in mind? What department? What person in that department?
Once you know who you should address, find out how you should address that person. How do you spell his or her name? How is it pronounced? Does she prefer Ms. or Mrs.? Is there a middle initial? A Jr., Sr., or Roman numeral? Find out.
5. Show that you identify with your reader’s concerns.
Explicitly state what you know about your audience’s interest in the idea you will propose or the problem you seek to solve. Show that you can see things from the reader’s perspective, and that you see the proposal as a win-win situation.
6. Quantify or specify the problem or need you seek to address.
If you can quantify the problem, you can show its magnitude and importance. Alternately, you might give an anecdote or example that helps highlight the importance of this problem to your audience.
7. Get to the point.
There are some cases where you may wish enigmatically to string your reader along before revealing your specific project. Usually, though, readers in business don’t have time to read a mystery novel. So don’t keep your reader waiting too long for your discussion of how you intend to solve the problem or respond to the recent trend you have identified. If you offer a deal, be up front about it. What are you offering? What do you want in return? Give your reader a forecast of what to expect.
8. Provide evidence or examples.
This is the key to a successful letter for this course. You must cite your research. You must also show that you can use the information you have collected to construct an effective argument for action. You might say that it requires putting information in action. Evidence is always logically persuasive.
9. Activate your reader’s imagination.
Invite your reader to engage with your idea, perhaps by using rhetorical questions. Get your reader to participate in your text.