A style guide recently instructed me to use a two-column format, saying "The two columns on the last page should be of approximately equal length." On the last page of my document, the first column goes to the end of the page and the second column goes halfway down. How do I balance this?
Add a Section Break (Continuous) just after the end of the text. It's invisible, but it will do the trick.
You can access this action in the Page Layout tab of the ribbon, in the Page Setup area, by clicking "Breaks" for a drop-down menu.