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.
Once you have written and organized your information according to the type of resume you have chosen, be sure to format it according to typical professional standards. You should use consistent spacing throughout, and evenly sized margins on all sides if possible. It’s generally best to stick to your word processor’s default settings, but in some cases, if you shrink the margins on the left, right, top and bottom, this can help buy more space to fit your resume on one page.