North Korea, like most developing countries, has poor mainstream water sanitation. Drinking tap water is not recommended. Whilst safe bottled water can be purchased in North Korean tourist shops, it is useful to bring in some bottled water just incase.
The food in North Korea given to tourists is of a good standard, however being a developing country you can never be so sure. Sometimes the food hygeine standards used in preparation can be lower. Resultantly its best precautions are brought with in the form of stomach and anti-diarrhoea medication just in case things go run.
gifts for guides
As part of visiting North Korea, the relationship you form with your tour guides is essential. The more they like you, the more they trust you, the more they trust you, the more they will let you see. The more you leave a good impression on them, the more you help North Korea's relations with the result. As a result, giving "gifts" to your guides when you meet them is a helpful option. It is recommended you buy cigarettes for the men and chocolates for the women.
As a tourist, when in North Korea you cannot use North Korean currency. Nor can you obtain it on international markets due to sanctions. North Korea takes a number of foreign currencies from tourists, most notably the US dollar, the Euro and the Chinese RMB. We recommend you use the Chinese RMB. Coming in from China, it is the most convenient to use, likewise, the North Korean regime charges considerably more when you pay for things in US dollars.
An SD card for your Camera or tablet
Sometimes when leaving North Korea, you may be made to go through a "censorship" in the exit. This involves handing over your camera and phone so they can search through it and delete content they don't like. To avoid this, bring an SD card and store backups of your photos on them so you don't loose what you took. Although to be honest, they aren't that "strict" on what they get rid of.
What NOT to Bring
Any religious literature Any literature in Korean Any literature critical of the North Korean government You don't need a flashlight, there is electricity in the hotel If you bring a laptop- they will want to search through it at the border