I try to match the Pokemon's typical personality to my classmates and sometimes judge based on physical appearance. For example, I have a mischievous friend in class so I chose Shaymin for him. Or my teacher, I chose Gardevoir for her because Gardevoir looks tall, pretty and mature just like her!
Wow, your class and my class is so ALIKE! Everyone barely listens to the teacher and they just bounce of the walls! I usually have to roar to get them all to shut up so I'm pretty handy in those kind of probems!