The letter format should use an appealing font. Maintain uniformity of font and size all through the body of the letter. At the same time, you should create headlines and titles to seem different by simply increasing the font size slightly. Capital or bold letters should be done with care so that reading continues to be smooth. The art of sales writing is time consuming. You could refer to a few sample letters to see how they have made good use of fonts to give a perfect finish.
Your cover letter format is very important to your success. With a high quality motivation letter, your chances at getting an interview will dramatically increase. Don't take shortcuts. Pay attention to both what you say (content) and how you say it (format). Your efforts will pay off in your career success!