For many years, Ardour has allowed you to save the current state of a session (basically, all settings but without any actual content) for use as a template to be used when creating a new session.
Starting in 3.0, you can now save the state of a particular track or bus as a template to be used when creating new tracks or busses. This means that you could, for example, set up your favorite vocal plugin chain along with I/O configurations and pan settings, and then recreate this type of track (or bus) instantly in any session. The only thing that isn’t saved, obviously, is the actual content of the track. To access this feature just right click on the name at the top of the mixer strip for the track. Its not currently accessible from the editor tracks, which was done because all the settings that will be saved in the template are really mix related.
Then, when creating a new track or bus, simply choose from the list of available templates and all tracks/busses created in that operation will use the chosen settings.