I like sitting where I am right now, in my X-Rocker gaming chair, laptop in my lap, and my feet propped up on the arms of the conventional office chair right in front of me. Usually I'll have music playing through the speakers in the gaming chair. A stack of books nearby makes a nice place to rest a cup of coffee or a bottle of Coke Zero.

Sometimes when I want a change, I move to the regular office chair and lean back with my feet propped on the edge of a book case that's nearby.

In either case, some variation of "leaning back with my feet propped up on something" is roughly where I prefer to be.

Rarely, I may program sitting in bed sitting upright with a bucnh of pillows behind my back.

morning: upright at a table at the coffee shop

after lunch: prone, sprawled out on the couch at home

Missionary position.