STEP 1- agressively grab another persons drink (perferably alcoholic) with one hand, and grabbing the collar of their shirt with the other.
STEP 2- Pull their face right close to yours and start chugging their drink.

Warning..Be sure to only do this act at the right time. for example, when your out drinkin' with good friends. Strangers don't like face chugs, but your friends will get a kick out of it....