Close up of Ushba in action
I use chest harness for extra security, and Ushba is attached to both chest and hip harness. I stop every few meters (when I find a good spot), and pull the rope through to make it more tight. The rope feeds through the Ushba ascender, but especially at the beginning of the climb, there is a slack and I help the rope a little bit; the feeding gets better as you climb higher.