This might seem obvious, but it is very important. Make sure your resume is updated with your most recent contact information. Recruiters and hiring managers often get thousands of resumes for one job position, so providing them with your email address, personal phone number, and home address will make contacting you for an interview much easier. When including your email address, be sure not to use addresses that are too casual.
Even if you are only sending in copies digitally, it is a good idea to print your resume (as it’s possible that hiring managers may be doing so) to be sure it prints on a single page, and is easy to read in printed form. Reading over a printed copy of your resume will also help you ensure that there is plenty of white space on the page and it looks professional.