The subject of cover letters is debated frequently on job related websites and you will find a lot of contradictory information regarding whether or not you need to include one. It is generally agreed upon that including a cover letter won’t hurt, as long as it’s well written.
Many resume writing services will also include cover letters as part of the package. These packages are fairly reasonable and the services provided are generally worth it. These people are professionals and have a great deal of insight as to what grabs a hiring manager’s attention.
A cover letter is not a bio, keep it short and sweet and stick to the facts. Any more than that will lose the attention of the reader and that’s the last thing you want. Your cover letter should outline why you believe you are qualified for the position, why you are interested in the position and why you believe that you would make a good fit. Nothing more than that.
Stay away from any negatives, or going into detail about your former employer and your reasons for looking elsewhere. Do not offer the information and only provide it if specifically asked. Salary expectations are also a big no-no. If the job posting specifically requires them give a very broad range of your historical earnings but make sure to also state that you are flexible and are willing to negotiate for the right opportunity.
Try to personalize the greeting. Standard “to whom this may concern” greetings suggest you are mass distributing your resume – even if you are, the idea can be off putting to potential hiring managers. Whenever possible, use the hiring manager’s name.
Avoid clichés like “attention to detail” and “multi-tasking” and find a more creative way to say them. Using the standard phrases will make your cover letter no different than every other letter they receive. You can say essentially the same thing but find an alternative way to say it. It will help your letter and resume stand out.
The same principles of advertising psychology that apply to your resume also apply to your cover letter. The human eye is drawn to blank open space. Space your paragraphs out and keep your sentences short and manageable. Less is more in this instance.