How funny! I do most of mine just opposite of Jen!
Most of the little girls I know around here have their hair pulled across from the left side of their head to the right. (Think of right/left from the child's perspective - I'm a biology major, so I always think in anatomical terms) It's just how their hair grows from the back of their head. I always have to make the open end of the clip on the left to help sweep the hair across right. Well, unless it's for a matched set which I do with a clip going each direction.
I love seeing topics like this to see how everyone does things differently!