What do you do when you get nervous or anxious? Scratch your nose, bite your nails, jiggle your leg or fidget?
What does your brother or best friend do? I'm a bit people watcher and love to see how people work and move. Even when I'm watching reality tv, I've seen a lot of excessive blinking, knuckle cracking, eye rolling, drumming fingers, hair flicking etc...
When I create a character I love to come up with quirky habits or mannerisms that sets that character apart from others or from the norm. Half the world bites their nails so that turns into a bit of a cliche if you only use that one. But how about some of these: humming without being aware of it, eating the entire way around your sandwich first, tapping teeth with a finger nail, gesturing wildly with hands while talking, not standing on pavement cracks... I'm interested in hearing your ideas too!
Actually I also get really annoyed by a few habits too eg: chewing gum with mouth open (yuck).
As for me when I answer the phone I use a different voice, I glance at my watch ALL THE TIME and I sniff (I HATE this particular one but it's really hard to get rid of) ;-)
What are your habits/mannerisms?