This is a simple tip, but one that not enough people know. If you like the look of San Francisco Mono and want to have it available in all apps on your Mac and not just Terminal and Xcode, you can run the following command from the command line and get this slick monospace font everywhere:
cp -R /Applications/Utilities/Terminal.app/Contents/Resources/Fonts/. /Library/Fonts/
Hat tip to Collin Donnell for reminding me of this trick.