Show name of template you are manipulating
From the Pages app, if you choose a page, click the General(?) dropdown between Form and Analytics, and go to Template.
From here, you can click Edit Template Properties. I use this section often to edit html on the fly after it's already been set up as a template.
This "Edit page template" page has the name of the site I am editing in General, but it doesn't in Layout (which is where I do most of my work here), so I often find myself having to save changes (before I want to) and go back to General or out of this page altogether to make sure I haven't lost track of what I'm editing.
It would be a simple change to add "You are editing X page" as a header under the Layout tab on the Edit page template page.