How to use a Bosun's Chair

I'm thinking of getting a Bosun's chair to help with a long time on a rope for photography. One thing I don't get though, is what the heck I rig it to (or maybe I do?).

For the most part I rap off a single fixed line or ascend a fixed line with two ascenders and then situate myself, sometimes with a second rope to angle myself. Do I attach the bosun's chair to the bottom loops of the ascenders and let it hang until I get to a level I want, and sit back into it?

Help me out please?

clip it to a prussic or ascender, maybe separate from your rig, maybe not. lower your weight into it. tie a backup knot if you're scared.

John Evans for Petzl, taught a great workshop on photographers use of Bosuns and ropes during a RocktoberFest weekend event at the Red a couple years ago. Possibly still some link to his notes on the Petzl website? Grigri and ascender were basic tools in use on a single fixed static line.