Identify the job by title and let the recipient know how you heard about it. Summarize your qualifications for the job, specifically your work experience, activities that show your leadership skills, and your educational background. Ask for an interview, stating where you can be reached and when you will be available. If your prospective employer is located in another city and you plan to visit the area, mention the dates for your trip. If you are applying for a specific job, include any information pertinent to the position that is not included in your resume.
Remember, you're hoping the person who receives your letter has no memory of your closing at all. The last thing you want is a hiring manager going into an HR meeting with your cover letter in hand, asking the team if they want to meet with "Mr. Kindest Personal Regards."