1. Always remember that you should not leave the table while other people are having food. Wait for them to finish after which you can leave.
2. Make sure that you remove your shoes before entering someone's home. Do follow this even for offices or shops.
3. Do remember that whenever you go somewhere, it is highly recommended to bring a small gift, like foreign wine or flowers for the host.
4. Be prepared to see people sniffing food or obtaining their second serving without being offered. It is quite common in Iceland.
5. Expect a lot of "Takk fyrir síðast" - thanks for last time. It is commonly used in Iceland instead of sorry or excuse me.
6. Never ever address people by their last names when you're in Iceland. Use first name along with title (if any) instead.
7. Do not ever give tips to anyone be it a bartender, waiter or a taxi driver. Tipping is seen as a strange thing and people might get offended.
8. Do not ask for bottled water if you want to avoid surprised looks on people's faces. Tap water in Iceland is pure and wonderful.
9. Never give something as a gift of thanks when you're living at someone's home, as it is considered rude.
10. Do not feel offended when people don't say sorry when they accidentally bump into you. People in Iceland generally don't say sorry.