Writing a strong letter of reference can help someone land their dream job. On the flip side, a poorly written letter could cost that same person the job. Knowing the difference -- between a good and bad letter -- is important. You can produce an excellent reference letter once you know a few simple tricks.

Background Details

A good letter of reference needs to be solid and informative. It should tell the reader as much as possible, while being direct and brief. To do this, you have to know the person you are recommending rather well -- or at least appear to. Writing a letter when you have little knowledge or not much to say could actually do more harm than good. Ask the person requesting the letter for background information, a template or even a sample letter to make the process easier.

Consider the Audience

Knowing the target of the letter is key in determining what to write. Write the letter for the position or purpose it serves, not just as a general recommendation. A letter recommending someone for a job should be focused on those skills and qualities the employer will value, given the industry or type of job.

Paint Pictures

Explain the reasons behind your praise. Explain what you have seen this person do. Give brief examples that place the praise in context and help the employer envision what this person is like. For example, if you write about punctuality, describe how Sam has worked for you for over five years and has never been late once -- even on snow days.

Your Image

While you might think that the job applicant is the only one being judged by your letter -- think again. Employers often take into consideration who wrote the letter. Be sure to maintain a professional tone and demeanor in your letter, be flawless with your grammar and list your title and qualifications, as appropriate.

Other Considerations

A thank-you today could be a lawsuit tomorrow. In some cases it is a good idea to get written consent from the person you are writing the letter for. Protect yourself and your credibility by being honest and only discussing what you know. If you do not feel comfortable writing the letter, decline the request.