If you're sending a hard-copy business letter, you're safest if you stick to a standard, traditional format. Purdue University suggests that you start with your own name and address -- unless it's in the letterhead -- and then the date underneath. Below that, write the recipient's name and address, then the salutation. If you send a lot of letters, you can save time by setting up a template in your computer.

Check Your Facts

You won't win customers or influence people if you get the basic facts wrong. The Emily Post Institute says you should be certain of the recipient's name and address, and the exact name of her business, before you mail off the letter. If the recipient's name is gender neutral, such as Pat or Sam, find out, if you can, whether you're writing to a man or woman. When you write the letter, proofread to confirm you spelled everything correctly.

Writing to Strangers

If you're writing to someone you don't know well, such as a potential customer, keep things formal using Ms., Mr. or Dr., as appropriate. If you don't know the gender, play it safe with "Dear Pat Smith." If all you have is a title such as sales director, "Dear Sales Director" is acceptable. However, Inc. magazine says that if you can find out the right name, that's preferable. If it's someone you've met, "Dear Pat" may be acceptable -- it's a judgment call you'll have to make.

Keep It Concise

When you're writing a business letter, keep it concise. If you have some connection -- you met at the Chamber of Commerce, a colleague recommended her -- you may want to bring that up, Xerox notes on its website. Then get to the point of the letter, which should be what's in it for the recipient. If it's a sales letter, for example, you want to bring up the advantages of buying from you. Don't approach it like an email blast, though -- even if you're sending out a dozen similar letters, make it as individual as possible.

Choose Words Carefully

If you're writing to someone within your company, your choice of salutation may depend not only on whether you've met her but on whether it's your supervisor, the CEO or one of your subordinates. The Public World consultant firm says that you should choose your words carefully to avoid anything coming back to hurt your career. Even if you're discussing a problem or sending a warning letter, keep a moderate, polite tone -- don't write when you're angry. Assume that whatever you say will not be kept private, because often it won't.