Pre-fill (templating) a new page

I'd like to see a way of “pre-filling” (templating) a new page with default data.

This could be usefull for shops/blogs to create consistency in the layout.
“create a new page based on X”
Then the X blank page could be prefilled with default header and page data.
A bit like this page for adding a new topic on the GetGrav forum…
“Pre Filled with ”Title“ and ”start a new topic".