I’m right-handed. I draw an O counterclockwise, instinctively, every time; I’ve never even thought about it until now. Counterclockwise, every time.
(Or, as a dickhead at work says: anticlockwise. What a douchebag. But that’s for another thread.)
A counterclockwise right handed North American. Drawing counterclockwise makes it easier to get the two ends to meet at the top, because your pen isn’t obscuring the view.
However, if you start drawing your circle at the bottom, rather than the top, then going clockwise gives better visibility.
That’s why you should draw circles while standing on your head.