I'm currently ironing the v2.0 of our One-Click Templates add-on to BlueGriffon. First version of that add-on is already a best-seller and I think you're going to like v2.0. Main changes are:
- nearly 3,000 (yes, three thousand) free HTML+CSS templates!
- you can now create your own One-Click Templates from any document of yours
So here's a static demo for you, click on the images to see a larger version.
First let's have a web document created inside BlueGriffon. For instance a blank page for the BlueGriffon web site:

We are going to turn that document - and all the objects linked to it (stylesheets, replaced elements, fonts) - into a personal template through the File > Save as Template menu entry:

The dialog it opens offers first to select where you want your templates and the associated database to be stored, and then set a few metadata for your template (mandatory unique name, description, license):

Once all choices are made, the dialog looks like:

And we only have to click on the Save button to create our template's package. Once it's done, the package's file is revealed by the OS. Please note the sqlite database for easier access to templates' metadata. All URLs inside our document or inside the associated stylesheets (including imported stylesheets, whatever the nesting level) are rewritten for cleaner packaging.

Now let's close our original document and use our new personal template. To do that, use the File > One-Click Templates menu entry

That opens the Template Manager. In the current version, 2864 free templates are available!

Just for fun, let's look at the templates proposed under Creative Commons Attribution 2.5 by freecsstemplates.org:

For each template, we have a thumbnail, a description if one is available, a license, an author, a button linking to a live demo if one is available and a button to select that template to create a new document. If a large preview image is available, clicking on the thumbnail will show it. Hitting the Select button to use the template requires only one last operation from you: you must provide a file name for your new document... Let's go back now to our personal templates, and here's the one we just created:

So let's create a new document based on our personal template. As I said earlier, I only have to provide a file name:

I'm all set. My new document is here. Wherever were the original files on my hard disk, I now have a "blank" document based on a template well packaged, all media files living together, all stylesheets living together, all fonts living together, all scripts living together for a greater maintainability.

Every time you'll use the File > Save as Template menu entry, it will remind you the location of the directory where your personal templates live in. Backing them up is then trivial and giving them to someone else is also trivial. Just give that person a copy of your templates directory...
This v2.0 is going live soon, don't miss it!
Update: images updated so they don't harm planet.mozilla.org