Yes, you can create your own templates and add them to Trail Blazer.

Using an outside HTML editor, simply copy the source HTML into the advanced tab page while editing your email. Once you have copied the HTML into Trail Blazer, click the [Normal] tab page. From here you can save the template by clicking the [Save Template] button from the upper Menu Bar from the email editor.

To use the template in the future click the [Insert Template] from the same menu then select your template title from the list given.