Pdarg - maybe I'm a loner on this, but here's my method.
As a preface, I should say when I lay down tracks I like to play to a drum beat rather than against a metronome click. This is why my approach is not the template approach.
I create a song and get it to my liking. It set up some busses and things that will be useful in any song. It also has a drum beat track. I use TTS-1 as my soft synth for playing that back. I actually start with this track included in the song ( as midi), and then add my additional tracks playing against that beat.
Then I save that file and quit Sonar.
In Windows, I copy the folder that contains that file/song and label the folder Blank Song rev1a.
Then I go into the folder and relabel the song/file as Blank Song rev1a.
And delete out any related drafts or Auto Saves.
Then I open the Blank Song file and remove the sounds, but keep the track structure - like a folder with electric guitar tracks and a folder with acoustic tracks etc. I also keep the drum beat track at the top of the file. After removing the particular song contents I then really have a blank song - except it has a familiar table setting as it were.
That's my starting template. When I start a new song I copy the folder and relabel the copy to the new song name. When I double click and open the file from the browser when it opens I have everything just as I want it and it's familiar so I can get creative right away. I can just set the tempo to whatever is right and the drum track being Midi keeps the beat.
I've done this for years and revise my starting file as I come up with improvements.
Since the starter file in this approach contains actual music content ( the drum beat) you can't do it from a saved template menu. Otherwise, without content the template menu approach works great for most users.