Concepts and workflows to listen to YouTube Music offline?

I would like to start a discussion on different concepts that community members use to gain offline access to YouTube content, particularly music.

I'm a heavy user of music found on YouTube because of its offered variety.

However, I would like to avoid to permanently stream the music online for two main reasons:

1. I need constant internet access which is not always a given (especially while traveling)

2. It consumes most likely less energy to play music offline than to stream it over and over again

Aside this background my question to the community:

What is your preferred workflow and method to have offline access to YouTube Music?

Thankfully,

Robert