One thing many foreigners do here that most Chinese don't is drink without ganbei-ing. If you are in a banquet situation, ganbei everytime you want to take a sip. It doesn't have to be the whole glass. The ganbei-er controls the amount. Be more aggressive and put a few of them under the table. If there are a few foreigners at the banquet, gang up on somebody like the FAO. Don't pick on the headmaster or party secretary unless you know it's ok but the FAO will HAVE to drink because his bosses are there. It's great fun to watch their face turn bright red and nearly explode. If it's lunch time and you are worried about classes in the afternoon, get the whole English department ripped.
Make them drink on your schedule not theirs.