We had a lecture on facial expressions over the past two days and I really found them interesting. I find body language and what people are REALLY saying really interesting and over the past couple of years I have learned about the quirks that I do when I'm feeling certain ways. I've also started to understand other people better by paying more attention to watch their saying with their gestures and eyes.
It takes me back to when I was a child and how me and my brother always knew when Dad was in a foul mood. He wouldn't shout or overly express he's not in a good mood, nor say anything. I don't remember anything in particular but when asked how we knew we always say he was 'giving off vibes'. When he did make appearances he was very detached from his surroundings and never made eye contact with anyone. Something about the way he walked told us to stay out of the way and he'd speak as little as possible if spoken to, if he chose to answer. That is about all I can remember but until starting university I never understood how we knew. Random train of thought!
Anyway, there is a person I follow on DeviantArt who does a lot of reference material included facial expressions. She's quite good and I've used her a lot for reference in drawings. I like how she just gets into a character and goes nuts! Here's a few links to examples:
I might try and experiment with facial expressions if I get the chance.