Include measurable accomplishments such as “increased revenue by 25%” as well as responsibilities. It is easy to get carried away describing your work experience or responsibilities, but keeping it short is crucial. Once you get an interview, you will be expected to go into deeper detail.
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.