If your résumé was viewed as being a list of your educational and job related strengths then your cover letter is essentially telling about those same skills in narrative form. The cover letter is a letter. It is meant to introduce you to a prospective employer or internship supervisor and to quickly mention one or two highlights from your educational strengths and one or two exceptional projects from school.
This is an opportunity to tell about what you are most proud of as a way of introducing yourself. These are the things that you are excited about, the things that interest you about design and the reasons why you would make a good person to hire as an employee or intern. If possible relate those experiences to the type of work that the firm you are applying to is doing. If you are unsure about this, don’t try to fake it or make something up.
Carefully state your interest and why you want to work for the company and why you think you’re just what they’re looking for. Generic flattery isn’t going to get you anywhere, but a reference to something, which caught your interest, might help and tells that you know something about the firm.
The cover letter accompanies the résumé. It covers it. It personalizes the sending of the résumé because the letter is addressed to someone specifically, whereas the résumé is not. The way your cover letter is written tells whether you did your homework before sending off the résumé. Misspelling the prospective employer’s name or that of the firm is definitely not a qualifying asset. Using the spell checker on the computer represents the very minimal effort at checking for potential mistakes. Take the time to do these steps correctly. Proofread slowly and carefully. Look for mistakes in grammar. Look also for mistakes or clumsiness in design. Then have a second person look also. Do not ask someone else to do this in a hurry or in a rush. That is not only bordering on rudeness but will also not yield very good results. Plan in advance to spend an appropriate amount of time on the design and writing of all of these application steps; letter, business card, résumé, etc.