I switch... I used to always point with my right hand, but then I tried the "official" bent left way, and if I have to ride one-handed, I do much prefer steerign with the right hand. I'm very right-handed. I also like stretching my spine a little when I'm doing the left thing and sitting really straight (and opening my chest like yoga).
But if I'm in traffic where there's a lot going on, I point with the right 'cause it's more obvious.
For left hand turns I got a red blinkie on my handlebar and I think I'll put one on the right too. Prob'ly not much good in the day, but on that ride home from work I like the 'expected' visual.