Making traffic signals on your bike?

[foxfirefey]

So, I have a vague idea of what traffic signals you're supposed to do on a bike. The problem is, I apparently don't always have the talent to bike *and* signal at the same time! I totally tumbled onto the road today trying to signal a right turn with my right arm.

Is there a better way? Does anybody have particular strategies? Should I just practice more in non-traffic areas until I'm more confident? Do they matter that much in your experience--how bad a sin is it to not do them?