When you think about it, the title of this post doesn’t appear to make sense. Yasnippet is a template system for adding customized boiler plate to an Emacs buffer. It’s raison d’être is to enable shortcuts for various programming constructs such as the C for loop.
Still, it’s a flexible system so it finds all sorts of uses. If you’re writing in LaTeX, it can help with things like the environment boilerplate. Similarly, it’s great for things like blog headers.
Erik L. Arneson has a post that describes how he uses Yasnippet for his writing. After explaining how to install Yasnippet, Arneson describes his uses. That turns out to be mostly things like blog headers and Org headers for certain other structured files. You can read his post for the details.
My personal use is almost entirely things like that. I never think to use it when I’m programming even though I do have the appropriate snippets loaded so the snippets I use are mostly for prose and various record keeping applications where the snippet provides a sort of form that I can easily fill out by tabbing through the fields.
The takeaway is that technology like Yasnippet doesn’t have a lot of application for writing prose except for headers and other boilerplate and perhaps for markup if you’re using something like LaTeX. Still, even those seemingly minimal applications can save a lot of time.