How to Type 《 》And 〈〉Efficiently on Mac Os X?

Solution 1: using Emacs

If you have an Emacs window open almost all the time like I do, you can use Emacs to do it, on macOS or other OSs. Specifically, Ctrl-x, Enter, then start typing the character's name, namely, "LEFT DOUBLE ANGLE BRACKET". As you finish typing more and more letters, type Tab to prompt a list of matching characters, until it auto-completes it to the unique one.