Learn a few words
-Not only gaining respect from locals for your curiosity to learn, you will also be able to negotiate better. Vietnamese spoke little English and so we learnt all the numbers to a 1000 (very easy system). Click here for essentials words to learn in Vietnamese.
We then started to work out an average price for a beer or a soup and would be able to state our price that we were used to paying.
The first thing that you should ask when wanting to order food/drink is; how much?
If you don't get this answer at the beginning, then you are left in an awkward situation at the end with nothing to stand on. Negotiate prior to ordering and sometimes even pay before to make matters even easier.