I use the all-left-hand signals--pointing left when I'm turning left, and pointing up when I'm turning right (I'm not sure what the equivalent may be in countries where you drive/ride on the left-hand side of the road). I do the best I can, but very often when turning I need both hands to slow down and control the turn, so my signals are often pretty short.

I LOVE the idea of turn signals on a bike (brake lights would be good too!), but I'd rather have turn signals on the ends of my handlebars than on the seat, because it would be more obvious which one is blinking.

I'm sorry you had a fall. I hope you'll be able to regain your confidence and get back out there!