Although the Google Drive desktop folder attempts to streamline access to your cloud storage space, it's easy to forget to save files there when it's not your default Documents folder.
People who count on Google Drive to back up and sync their documents can create a more seamless experience by changing the default Documents folder to Google Drive. After doing so, Windows will automatically choose Google Drive as the default save location when creating new documents. Here's how:
Windows: Right-click your Documents folder and select Properties. Select "Include a folder..." and locate your Google Drive folder. Then highlight Google Drive in the list above, and select "Set save location." Apply changes, and you're set.
Next time you save a document in a program like Microsoft Word, Google Drive will be selected as the default save location.
Mac: Open Terminal (search for it in Spotlight) and type cd Users/yourusername/Google\Drive. Hit Enter, then type ln -s ~/Documents /Documents. Hit Enter.