I have unsuccessfully tried on sofa. I have always felt comfortable on bed but, since I have the desk right in front of me while I am online, I am wondering if it is comfortable to be sitting on a chair in front of the desk, like in an office...
Since my cats are gone I will be using my whole apartment to cam from. I have my bedroom set up now where I can have desk and also a console table at the foot of the bed. You definitely want to move around if you can. because your muscle will take a beating if you don't
There is no perfect set up, just make sure you are comfortable and you background looks good on camera. and move around and take breaks when you can. I am going to be probably getting fitbit that will alarm for move breaks.
until I Get one I set the alarm for every hour to move. while I'm online