How To Make a Simple Hand Rig in Blender! (pose transitions with a single bone!)

This is a super basic tutorial on transitioning between poses (something I learned recently
I hope you guys enjoy and ill do my best to help with issues y'all might be having! But I'm also kinda new to this stuff so an suggestions will be greatly appreciated!
Around 3:33 is where I show the pose transition stuff so if you already have a rig, and model just skip to there.