I try to stand as much as possible when working, but I do need to change it up as standing all day is hard on the feet and back. Here is my current setup for sitting that seems to be working best
Seat is free to rock.
Seat with a slight lean back till back is comfy.
Arm Rests 3 notches up (90 degree arm bend)
Keyboard Tray is pretty level with arm rests
Legs are 90 degrees
Single Monitor in front about 2-3" above eyes
Second monitor to the side in vertical mode for notes and chat