There exists within the WP CLI the scaffold command which allows you to easily create the base file and folder structure of some common WordPress features, like Plugins, post-types, or a theme based on Automattic's _s. If you're going experimenting with the new Gutenberg Editor slated for a Core Release in 5.0 there's also the block generator. If you don't currently utilize Boilerplates such as WPPB then using the scaffold feature of WP CLI can definitely help speed up your workflow
What does it do?
There's multiple sub-commands for the scaffold command.
wp scaffold block – Generate the PHP, JS, and CSS files for creating your own Gutenberg block. I would definitely recommend this as a starting point for diving into creating custom blocks, especially since Gutenberg is slated for WordPress 5.0.
wp scaffold child-theme – If you use a framework such as Genesis, or Divi, or any other theme but need to get a child theme setup rapidly without manually copying/pasting files or creating them from scratch then this should shave some time off the initial setup.
wp scaffold plugin – Get a decent head start on developing a new plugin. I personally prefer using the WordPress Plugin Boilerplate because it gets setup for Object Orient Programming utilizing classes, so it gives you an even better headstart than scaffolding one.
wp scaffold plugin-tests – This will generate files for your plugin to run PHP Unit Testing on.
wp scaffold post-type – Whether you're needing to get some post types added to your theme or for your plugin this command will generate all the necessary PHP code to register, and add a Custom Post Type to your plugin or theme, or just output the PHP code onto your Terminal for you to copy and paste it into a specific theme or plugin file.
wp scaffold taxonomy – Similar to the post-type command, this generates the PHP code necessary to setup custom taxonomies faster than having to manually type everything out, or saved somewhere as a template and then having to search and replace the necessary fields.
wp scaffold theme-test – Just like the plugin-tests this generates PHP Unit Test files around your theme.
wp scaffold _s – This works exactly like downloading a fresh file for Automattic's Starter Theme Underscores or more simply put _s. You can pass all of the same arguments on the command line as you fill out on their website. It would be great to see WP CLI change the plugin scaffold command to use the WPPB setup that I've mentioned before, as their generator site works exactly the same as the _s website. If you need to create new themes and you prefer working with raw code starting from the bottom this is your best asset. I would like to see the addition of being able to choose some kind of CSS framework to add by default such as Bootstrap or Foundation as that could save additional time.
Wrapping it up.
For the full list of commands and more documentation I recommend reading over the Developer Handbook page.
Hopefully you find some usefulness to the scaffold command. Most local environments such as Wocker, or VVV will contain implementations of the WP CLI that are fully featured. Some web hosts that grant CLI access may turn off the scaffold command, but that's due to developers scaffolding and programming locally before pushing things up with Git or another kind of development tool. WP CLI should be a part of any developer toolkit and can help speed up your workflow as you become more comfortable with it.