My wife and I started a YouTube channel. All of the videos there (as you can tell, it’s very recent!) are made with Ardour (audio recording is done with Ardour, then A/V processing is done with Shotcut)
I love having a fully FLOSS workflow - Ardour + Shotcut on Linux
I used to create my own using a combination of playing stuff on our keyboard, MIDI, etc, but it got too much and I just switched to professional karaoke trakcs. Haven’t created karaoke tracks from scratch for a good decade now