Scissor on a round rail. However if it's a flat bar, a box etc, once you move in one direction, balance on your back foot and pick your front up and put it on the side of the box, then pull yourself around pretz. Here's a vid of my boy hackel to show you just how to be a boss
https://www.newschoolers.com/membervideo/612376.0/Afternoon-At-Sunday-river-?s=20034&t=6&o=8