This is my current setup. After my laptop has shut down twice on its own from overheating, I now prop it up on our coffee table tray. I used to sit my laptop on top of a pillow on my legs, but apparently this is a big no-no for ventilation purposes.
I move the coffee table all the way against the couch and sit with my legs crossed in front of me. It is really uncomfortable, but I like it more than sitting at a desk all day. I am a true couch potato. Perhaps I should just invest in a laptop cooling fan?