Vietnam Sunrise Travel Co.,Ltd

• It's in your best interests not to drink the tap water, especially after flooding!
• Avoid cyclo ride after dark.
• Dress modestly and appropriately when visiting local dwellings and religious sites, etc.
• Leave your valuables behind before a night out on the town, or going to the beach.
• When crossing the road, especially in Ho Chi Minh city, always keep looking to the left and right and walk slowly! 
• Do not offer money directly to minority people - instead donate to a local charity or offer a small gift, such as pens.
• Try at least once the delicious, local street food.
• Always ask permission first before taking photographs, especially in the minority areas.

(Source: Vietnamtourism)