Whenever possible, don't send a "blind" cover letter, which is a letter that isn't addressed to the individual you want to secure an interview with. Lack of a specific address can give your prospective employer a first impression that you were too lazy to find out the person's name. Investigate the company by researching its website and asking any associates you know there to determine the name of the individual hiring for the job. If you can't find the name, make the salutation sound as professional as possible.
Avoid using a generic address like "To whom it may concern," or one that is overly friendly, like "Hi there!" These salutations sound unprofessional. Also, people often skim letters from unknown senders. If you don't give the reader some direction as to where the letter should be forwarded, they might throw it away.
Don't guess the recipient's gender based on the position you are applying for and write "Dear sir" or "Dear madam." A woman could decide who will fill a job in male-dominated profession, like carpentry, and a man might be reviewing candidates for a nursing job.
Use an address like, "Dear recruiter" or "Dear executive." You can also use "Dear hiring manager" and add the name of the position you are seeking (for example, "Dear hiring manager for Newsweek's entertainment reporter opportunity").
Check your grammar, punctuation and spelling. Verify that you addressed the right company and specified the right position. You might accidentally write "Dear McDonald's service manager" when applying at Burger King, or write, "Dear restaurant waitstaff manager," when you meant to address it to "Dear restaurant food manager."