Little things I have noticed

When pointing to something, use your whole hand. I learned this when I was in Japan. Pointing as we do in the US is rude.

In Vietnam they often use the spoon along with chop sticks. It helps with slurping soup and noodles. And slurping seems to be just fine...not quite as loud as in Japan but it is no condoned like the US.

Frequently a spoon and fork is given for food. The spoon is used as a cutting utensil. I really just wanted to pick up the drum stick and eat it with my hands but I am sure i would be viewed as some barbarian so I refrained.

Utensils are faced down when taking a break from eating. When you are done you face them up.

Leave some food over on the plate. It shows you were well fed and there was more than enough when someone else is providing. Still getting used to this one but is useful when you don't like the food.

Bathrooms- Its a BYOTP. Everything from newspapers, loose leaf, cloth are used. It goes in the garbage and not the toilet. They also have a garden hose attached to the wall. I will not go into explaining but I am sure you catch the drift.

Pepsi and Beer you are in the clear, but tea you should fear.
I still drank it when it was offered but try to avoid it along with vegetables you boat captain offers you.