This video is pretty outdated. Please only use it if you're already familiar with Unity or making avatars with SDK3. I will eventually have a video out that is much more beginner friendly.
This video goes over how to implement your own idle animations on your 3.0 avatar! The default animations can look a bit questionable at times, so replacing them with your own is certainly useful.
(Please help me with these thumbnails. I'm running out of colors.)
Animations: https://drive.google.com/file/d/1B0L5wOmGb9iBXRp85iAtJ49BSG-YZwQ1/view?usp=sharing
Music used: https://youtu.be/oSi7lD-SNQw