Vietnam is a generally safe country but like anywhere else, a little common sense should keep you out of harm’s way. Traffic accidents are not uncommon in cities and towns so crossing the street should be done with care. Pickpockets and thieves are an issue: keep an eye on personal belongings in public and avoid ostentatious displays of wealth. Bar areas can be less safe late at night compared to other parts of a city. If you have a disagreement with a taxi driver or vendor, keep your voice level low and don’t escalate.
Despite usually being friendly to foreigners, many Vietnamese see no problem whatsoever in charging them more for goods or services. Make sure that prices are as clear as possible before making a purchase and only ride in taxis with meters. When booking a tour be clear about what is and is not included in the price. There is no foolproof way to avoid being occasionally overcharged and sometimes it’s easier to just let it go, especially since it’s usually not a lot of money.