When I first started teaching business and technical writing, I didn't think that I was going to see so many horrible resumes. But I did... So I became the Resume Master. Seriously.
Obviously, the information on your resume depends on your experience, where you are in your career, and where you want to go with your career. Regardless, there are a three essential things that can make your resume stronger:
Having strong alignment makes your resume look stronger (no matter what is actually on it). Use tables in Word to insure that you are using the whole page. Commonly, resumes are aligned with information on the left and dates on the right; this is fine, but you have to make sure your dates on the right are perfectly aligned.
Students seeking their first professional jobs should use only two alignments and create three vertical lines of negative space (one on each side and one between the longer and shorter content in the document).
Students later in their careers should, also, use only two alignments, but only have two lines of vertical space. (This is just because with more experience there is less white space that needs to be visually organized.)
2. Emphasis and Focus
Make sure you're writing your resume for your potential employer. I show my students two of my resumes: one for a position as a professional writer and one for a position as a dog blogger. Check out my examples, and notice how the content fits the needs of the potential employer (not my need to brag).
Our eyes "read" resumes by skimming. Only if we find something interesting will we actually read a resume. So make sure that you have clear categories, bulletted lists of additional information, and strong verbs describing your experience. Also make sure your resume contains the keywords from the job search.