The document should have a consistent and professional look. Do not feel limited by the margins a computer program gives you, the resume you used to have, or the layout that other people use. Because your background/experience is unique, your resume can be too.
Highlight key information by placement on the page as well as the use of formatting tools, such as bold, italics, all caps, etc. The more you use formatting, the less effective it can be, so use these elements carefully. Proper size ranges from 10-12 for the traditional Times New Roman typeface. Your name, as the main header of the entire document, should be bigger. And category headers can be a bit bigger. If you use a different font, make sure it is easy to read. Don’t use special characters that not everyone will have.
The very process of creating and updating your resume is an exercise in self-assessment that is key to the job search and interviewing. Being very familiar with your accomplishments, skills, and areas of expertise are crucial. Who knows you better than yourself?