is there a tutorial on how to tweak clj-new to create a custom template?

You can create a new template project and build one from that -- which can then be used via a local file reference, via a git URL, or built into a JAR and published to Clojars. But the docs around it are very poor right now and the generated template project is extremely minimal.

Now that tools.build is available, I plan to produce a new version of clj-new that leverages that library to copy entire directory trees and perform the text substitutions that clj-new currently uses Stencil for. That will be a much easier process.

ok. Do keep me us all informed... I'd very much like to use this functionality. Thanks a lot for all your help!!

The arrival of tools.build has really changed the landscape in terms of what clj-new could/should do...