Before each trip, you should prepare enough items to bring to avoid being embarrassing or unnecessary worries. It's a good idea to have a list of essential items and check to make sure you do not forget anything.
When teaching English in Vietnam, which certification that Filipino may need? How to get a visa to Vietnam for Filipino passport holders?
This post addresses 2 methods to get Vietnam Visa Application Form: Through Internet or Through Vietnam Consulate/ Vietnam Embassy in Hongkong.