This is a long delayed post, concerning food etiquette, especially among the chinese. Chinese are most fussy about such stuff (especially Edmond [rite, chee wee?]), and if you're at dinner with your chinois boss and his tai tai (or his mistress, heh.), the importance of food etiquette is quintessential.
Ok, so what are there to observe? From the limited knowledge I have :
1) Never never cross your chopsticks and show that you don't know how to use them! Showing your inaptness at wielding these two pieces of wooden sticks might extrapolate to an inability at any simple jobs in your boss' eyes. So must up your level on this. The most effective and arduous trainings for this include picking fishballs out of soups, and moving delicate pieces of beancurd around. Also, never stick your chopsticks into the rice to resemble incense offerings at an altar, for obvious reasons.
2) When eating rice off your bowl, it is ok to hold the bowl in your hand, but NEVER ok to hold it such that the bottom of the bowl is in your palm. It resembles a beggar begging for alms, and is certainly the image that you don't want to portray.
3) Scrapping off your bowl and slurping is supposedly OK to the traditional Chinese, but I beg to differ. Cos it's simply bad manners in western culture, and with so much fusion of culture going on, it's a safer bet to ignore both acts altogether.
4) Chew with your mouth CLOSED. I've noticed a lot of pple unconsciously chew with their mouth sometimes open. Though I'm quite ok with this, except for situations where I can see vividly the ingestions of the eater, some people are quite particular about this. In doubt, err on the safe side and make a conscious effort to keep the mouth closed.
5) Taking food from the center of the table and putting it directly into your mouth is regarded as impolite. Normally, the Chinese would pick the food and put it into their bowls first. So do that. In situations where there're common utensils, USE THEM! It's a matter of hygiene that I'm quite partial to, unless I'm really lazy that day and everyone's chummy.
6) TEA. To ask for a refill, simply turn over the pot cover and place it at the top of the pot's opening. As a matter of courtesy, refill the cups of your fellow diners first before turning to yours, even when theirs is not empty. And never extend your pinkie outwards when you drink. If people serve you tea, use the middle section of your index and middle fingers to knock against the table as a gesture of thanks. There's a story concerning this - When emperor Qian Long travelled incognito, he once served his accompanying official some tea. Because the official cannot kneel on the floor to show his thanks to the emperor, he used his index and middle fingers to knock against the table as a symbol for kneeling on the floor to show his thanks. So there. Your server is not an emperor, but it's never unflattering to show him similar regards.
7) Let the more important guests start first to choose their preferred parts of the dish. Also, it is important to not overeat your share, especially in dishes where there are discrete amounts of food (like fried wantons, fried fishballs, pieces of chicken wings++). Always eat your share, and leave remainder sums on the table for polite offerings later.
8) Turning over a fish is considered bad luck to strict Chinese tradionalists - they rather remove the skeletal bones directly off the fish then turn it. But I'm quite fine with not observing this, cos most people don't. It's just not efficient.
9) If you use a toothpick, please cover your mouth with the other hand to reveal less details to your fellow friends.
10) Burping? Not fine.
Yup, that's all I know. Do you know any other?
During meals with friends, I have always noticed the LPS - the Last Piece Syndrome. It has always been a source of awkward silence - who will take the last piece?? Will it be offered to me?? For goodness sake, someone just eat the last piece!! I can't stand it!! I'M GOING CRAZY!!! SOMEONE JUST EAT IT UP!!!! ARG! ARHG!
This is a situation that I have no foolproof solution to, but some of these might work:
1) Don't let it exist in the first place! Once someone has taken the second last piece, wait a short pause and whack the bugger off the plate in the most unassuming of manners. The pause is to normalise behaviour and let pple know that you're not so gian about the food. Hopefully you won't be the only one doing this after your gambit, else it'll look bad on you to finish ALL the last pieces. Or you can just bochup what they think, and think of yourself as a saviour who prevented the LPS from taking place. You're worthy... *nods head slowly*
2) If the LP is there already, you need a distraction. It'd best be an external distraction, like the waiter serving tea, or someone's phone ringing. Else you can also think of an interesting topic that captures the thoughts of everyone for the short while, while you surreptiously swipe the LP off its feet. If you can't think of an interesting topic, try asking them to calculate a mathematical question ('What's root b-squared minus two A B, over two A?', or the conventional '5 men builds 1 house in 2 days' question)
3) Take initiative and assign pieces to people as fairly as possible.
4) Offer them randomly.
The last piece is often seen as the most delicious piece of the whole lot (Choji will agree to this), but it's really not the case. It's just another piece. So don't fret if you don't get the LP.
Who am I kidding? The last piece IS the most delicious piece, so grab it first while you have the chance! =P