One of the most important things your resume can say about you—before anyone reads a word—is that you are a professional. How does the resume say that? It is formatted cleanly, with your name and content information clearly visible on top and with consistent alignment, font size, and bolding or italics. On closer inspection, it uses standard English spelling and grammar.
Once hiring managers or recruiters begin to read the resume, it should say that you are qualified for a specific position and meet the requirements of the opening the hiring manager or recruiter wants to fill. How does the resume say that? It begins with these three items: a clear statement of the job you want to apply for, a profile that stresses your most important past achievements, and a list of your skills (especially those that line up with the requirements for the job you want).
Your resume should then assert that you are the best candidate for the job. How does the resume say that? It provides bullet points that home in on your achievements, the way you used your skills and experience to benefit your past employers. It is very specific about those achievements, including the exact results you achieved either by yourself or as part of a team and any recognition you received for those results. If you are applying for a leadership position, your resume should contain examples of mentoring and motivating others, cooperating across divisions or companies, and making difficult decisions.
Finally, your resume should show that you are a continual learner and contributor to your community. How does the resume say that? It concludes with your education, memberships in professional and nonprofit organizations, licenses, and certifications.
You never want your resume to say that you are sloppy, inattentive to detail, desperate for any job at all, whether you are qualified or not, difficult to work with, and unwilling to learn more and take chances.