Here's VERY important tip to all you of you pivoteers out there!
the tip is: Always try to move more than 1 joint in an animation to remove stiffness, and it gets better as there become more easing and multiple joint movements...
i hope this tip helped! ( i know this only because ive been pivoting for a year now, at Droidz.org baby that place has all your pivot satisfaction-needs, from tutorials to stick figures, tips, pivot collabs, joints, etc.)