I actuallyhave an extension ladder that is a dedicated hanger I place it against the tree, run a rachet strap around the middle rung and the tree and tighten. it gives me a steady base to go up and do what I have to do. i like it better thna a linemans belt becuase I feel more secure, But I still wear a harnes when I am at the top installing the thing. after I have it up I put on the tree steps, or I have even just left the ladder. works great, and its fast.
Good luck and be safe