Of all the new features in macOS Sierra, one of my favorites is this really simple one that changes the way files and folders are displayed in the Finder. (Hat tip to former Macworld editor Scholle McFarland for pointing this out.)
When you open a Finder window and then sort or arrange the window based on name, everything is listed alphabetically, and folders are mixed in with files. This is the default in Sierra, and has been the default in the Mac operating system for as long as I can remember. My preference, however is to have the folders appear in the list first, so I used to name my folders with a blank space as the first character in the name (for example, “ Stuff” instead of “Stuff”).