When talking to someone and walking, make sure you look in front of you, not at the person. Otherwise the wrath of other people, poles and walls come into play. :doh:
When talking to girls, do not talk to them when there are people such as LI around...

you will pay for it for weeks to come.
When in class or walking around, do not ridicule the teacher when they are in earshot (happened to Sophie...now that was funny). Especially when that teacher is the mother of your friend (I just hope that she forgot...I really do).