Writing a great cover letter is arguably the most important part of your job application process. Of course your resume will clearly outline your specific experience, skills, and qualifications. But your cover letter is your chance to set yourself apart from other applicants that may have similar qualifications.

Unfortunately, many job applicants submit mediocre cover letters and miss an opportunity to get ahead of the pack. In fact, many employers say that cover letters—not resumes—are often the deciding factor in their search for a new employee.

So how do you write that killer cover letter that will get you the job? It's easier than you think. But in order to write a great cover letter, you have to know the dos and don'ts of writing a great cover letter.

Use proper grammar and spelling. It seems like a no-brainer, but you should never submit a cover letter with grammatical and spelling errors. A clean, accurate cover letter will show that you are thorough and pay attention to detail, not to mention exemplify professionalism.

Keep it short and sweet. When writing about yourself, it's easy to ramble on and on. But a succinct yet thorough cover letter will demonstrate your communication skills and be more inviting to read. A few short paragraphs are all you need.

Be professional. A cover letter seems like a great opportunity to show your personality. And it is. But save your sense of humor for another day. Humor rarely comes off as it was intended in a cover letter. In general, it's best to keep a professional and straight forward tone.

Highlight your strengths. Even if you're slightly under qualified for the job, never mention your weaknesses in your cover letter. The cover letter is a place for you to shine.

Explain why you're applying. Tell the employer in your cover letter why you want the position. State the position you're applying for right up front and explain why you're interested in that job with their firm. This is a great opportunity to impress the reader by showing that you've done your homework as well as demonstrate your passion for the position or industry.

Explain what's in it for them. When hiring a new position, employers want to know what you can bring to their organization. Identify the contributions you'll make to their firm and how they can benefit from hiring you.

Say thank you. At the end of your cover letter, always thank the reader for taking the time to read your letter. It's also an ideal place to declare your plans to follow up on your application. Let them know they'll be hearing from you and that you intend to take action, instead of waiting for them to call you.

Writing a great cover letter gives your potential employer an opportunity to learn more about you than what's on your resume. Never miss this opportunity to impress your reader and get the job you've always wanted.