A nation's culture is the product of its history and traditions. Germany has a lot of cultural elements closely related to its European counterparts; still it does adopt its own set of lifestyle guidelines that you would benefit from knowing and appropriating if you’re thinking of moving to Berlin.
The first thing you need to know about Berlin is that it is more of an island surrounded by Germany than a part of Germany itself. Berlin sort of makes its own rules. Because Berlin is an international metropolis, it not only attracts foreigners, but also Germans from all over the nation. Therefore, the concept of German traditions and lifestyle remains.
At Work
In the workplace is where you will encounter most of these unspoken rules. Though Berliners are not as prompt as the German cliché would want them to be, you still need to be punctual at work.
Germans also expect to hire you to do a good job. They will very rarely tell you when you do a good job but rather let you know when you’re not performing well. As such, you will most likely have to go claim your raise or bonus.
Do not interrupt anyone when they are talking. It’s fine in France and Italy, but it is a big insult in Germany.
At the Dinner table
It is common to wait until everyone has been served their meals before you eat, unless someone who hasn’t been served suggests it is fine for you to dig in.
It will also be appreciated if you say "lass(t) es dir (euch) schmecken," meaning "enjoy your meal." If someone says it before, you can simply reply "eben so."
Common Courtesy
In everyday life, it is good to know that Germans greet each other even if they don’t know each other or have never seen them before. It is seen as a common courtesy gesture that is just done. In Berlin, due to the large foreign demographic, it is not expected but appreciated.
In general, if you do not know a person, start addressing them with "Sie," which is the polite form of you or "Du." If a person is young, it is usually accepted to refer to him as "Du."
German Recyclers
Germans love their environment. They try to lower their carbon footprints as much as they can. Berlin may look dirty, but the broken glass and overload of trash is usually the work of younger folk and so-called “alternatives” that really everyone despises for their lack of respect.
So far, I have met many Berliners and Germans from all walks of life from artists to DJs, from entrepreneurs to comedians, all of whom abide by the recycling guidelines. The glass goes in the container of its rightful color, biodegradables are gathered together, as is paper and cardboard. Plastic and packaging are gathered together, and finally there is a separate entity for all trash that cannot be categorized in the above containers. In Berlin you will see a lot of bottles and cans gather under a public bin. This is OK, because these bottles have a "pfand" waiting for them at every supermarket. Bring your own bottles yourself to get the recycling money back.