What to bring to Vietnam??
For the summer, it's important to have: mosquitos spray, hat, sunglasses, sun cream, raincoat, swimming suit, international charger, and of course your camera and phone! Trekking equipment if you want to trek. While a lot of these can be acquired once arrived in Vietnam with a cheap price, it's also important to bring them in advance, preventing you from wasting time to find what you need urgently without speaking the language. For the winter, you'll need warm clothes, especially if you're planning to go further in the North, where sometimes it can actually snow. The humidity here is high, so the cold gets to you faster. A travel guide book, and learning some basic words to communicate, are a plus. Bring some vietnamese money, if you need to spend right away, some places don't have a card machine, so you can exchange money once arrived in Vietnam or cash out from the ATM to simplify your trip. If you have an international sim card, it's good enough, otherwise, get a local sim card for 2$ only, to have Internet and use maps. Most places in Vietnam have free wifi.