for the smile and shouting one i didnt use any ref, but for the other 2 which was a bit more complicated of an expression, for me anyways, i used a web cam. hehe
Geee.. YOu certainly got a lot of patient on that hair. For me, personally I love all the details. But if I were to draw a comic, or maybe animations, I would scale down the details just so I could get everything done easier and faster. If I were to focus on details, maybe more on the background instead. But, details is goooooood.... Details makes things looks nicee... Me like