Strap Rig
This was a lot of fun to design. Here's my curly strap rig, showing off its automatic placement onto the inside of the knee. Further, the animator can move, rotate, and scale all of the box controllers individually, or with the main strap controller. And scaling it makes the strap curl!
Here's me scaling it
(on an older version with a very thin strap)
Here's me editing the parts individually
(on an older version with a very thin strap)
Further explanation and updates on my blog post about this: