Don't overdo graphics, use of color or fonts. Avoid cuteness, puns, jokes and shock effects. Do write straight-forward, business style. Avoid making your letter look like junk mail, with too many bold-faced, underlined words. Check all spelling and grammar.
Many employers read the first paragraph and then scan the rest.
Tie your interests quickly into the interests of the company. State what you can do for the company. Ask for a personal meeting in an undemanding way. The Hook First sentence must intrigue, capture attention and hold interest. The IMC Connection Highlight course work, class consulting projects, Residency that support your qualifications for a specific position or generate more attention to you overall.