Have you ever created several documents in a row and set up more or less the same grid layout for each page? Becomes a hassle after a few pages, doesn't it? Distress no more! Here's a package that let's you create default layouts for your grids to get a flying start.

TL;DR: There's a video at the bottom.

Word to the wise

This is an alpha, and it's probably still got some quirks. We use it in production for all our newer sites, so it should be quite safe. However, if you're going to modify your existing grids:
MAKE SURE YOU NOTE DOWN THE CONFIGURATION!
The data type will reset back to the default grid settings when you change the property editor.
You could probably just change the property editor alias in the database, but I'll leave that for the savvy ones.
There's one other drawback, namely that it cannot be set up properly when using the document type editor to edit the datatype.

Usage

In addition to the built-in prevalues for layout and RTE configuration, there is an additional prevalue for the default layout. Add rows and editors like in a regular document, until you've got a nice starting point for all pages.
NB! When changing the layout configuration, especially renaming things, you may have to use the "Reset layout" button to be able to create a new layout.

Core potential

I've made a PR for this to be part of the core since I believe it's a pretty useful feature for many sites. Feel free to give the issue a vote if you'd like to see it built-in too. By "popular" demand, I decided to release it as a package for better community support. Thanks, Lee! :)

Oh shut up, just show me how it works

Aww, OK. At least I hope I got some proper SEO out of the babble above. :)