1. Use an email address which presents a professional or at least neutral image. Avoid such names as : sweetie pie; hot4u; road racer; etc. While these may be just fine for your general correspondence, they are an immediate turn off to a potential employer looking for a conforming employee.
2. Capitalize your name correctly;
3. Don't use all caps, except possibly in the title line of the resume.
4. Read the ad, apply for the right position. Don't send a cover letter looking for dental assistant work to a job opening for an office worker.
5. Include all relevant information. Don't skip jobs, don't lie.
6. Spell Check.