Hi,
It's indeed a very important topic, and mastering quaternions action will make your life easier!
the first thing to do is to read documentation on this in Unity, as the quaternion actions simply exposes these methods that you script in c#.
https://docs.unity3d.com/ScriptReference/Quaternion.htmlThen you can get the
Ecosystem and search for samples on quaternions:
Get them samples ( make a dedicated projects for PlayMaker samples so that you don't overload your projects with them).
a simple one is the tipping cube, the logic to get the right axis and all is not important, focus on the "animate" state of the TippingCube" Fsm, it uses QuaternionRotateTowards and shows you how to animate a transform that way with total flexibility, something you can achieve with tweening engines too, but here I show you how to do that manually.
If you have then questions on a particular use for a specific result or specific Action, let me know, it will be easier to answer precisly.
Bye,
Jean