Explain why you are writing the letter. In this article, we'll share the top 6 tips for writing a powerful cover letter and hopefully help you land the job you want.I generally don't look at applications without a cover letter. The best cover letters effectively communicate the candidate's qualifications, enthusiasm, and fit for the role. A cover letter usually is three paragraphs long and outlines why you are applying for a specific position, a brief overview of your professional background.