In Berlin, there was a smoking ban for all restaurants, bars, discos, and public areas. This ban has been partially suspended by the Federal Court of Justice, so that for the moment smoking is allowed provided that the location indicates this at the entrance. In some locations you will find an extra smoking room.
Do not turn up late for an appointment. Germans are extremely punctual, and even a few minutes’ delay can offend (even though amongst young people, these rules might be less strict). Be five to ten minutes early for important appointments and be sure to call the person you are meeting if you really cannot make it in time. At big parties with lots of guests on the other hand, punctuality is not an issue.
When entering an office, it is common to knock first, wait for the Herein (engl.: come in) and then enter the room. Office doors in Germany are usually kept shut, but even when they are open, it is polite to knock before you enter the room.
It is an act of courtesy to bring a little gift, e.g. a bottle of wine, chocolate, or some flowers, if you are invited to a German home on some social occasion. If the flowers are wrapped in paper, remember to take off the wrapping just before you enter the home. It is considered thoughtful to thank your host for the invitation one day later, either in person or by phone.
When you meet Germans for the first time, you might get the impression that they are a bit reserved and cold. So do not be offended when it takes a while until you receive the first private invitation from your new acquaintances. You could try to shorten the slow way of getting to know each other and take the initiative by inviting them to your place or suggesting to do something together. Once the initial difficulties are overcome, genuine and long lasting friendship can develop.
At Christmas, you should not expect to get an invitation to a German home. Christmas in Germany is regarded as a family celebration or a get together with family members only.
Clothing is a matter of fashion, and in most areas of life, there are no clothing rules. Although an official suit and tie is regarded as the “correct” clothing in business life, at universities and other research establishments, clothing is less formal. It depends on faculties and regions but more importantly on the position within an institution. Anyhow, people are often judged by their dress. Especially at evening events (e.g. concerts, theater, speeches), you should therefore not dress too casually.