DO'S & DON'TS
1) SEPARATE ALL YOUR TRASH (MÜLLTRENNUNG)
This is the most important habit that you need to practice, especially if you are staying with a host family. Make sure you separate all your waste into specific trash cans. There are usually at least 3 trash containers at your home. The black one is for the Restmüll (Residual waste),the yellow one is for the Verpackung (packaging) yellow one & the blue one which is for Papier (paper).
2) DON'T EVER RAISE YOUR HANDS IN A WAY THAT IT RESEMBLES THE NAZI SALUTE
It is normal for us to use our hand when we wait for a bus. But be careful as to how you are positioning your hand as a slight different placement of your arm can actually cause you to create a scene! The whole issue of WW2 and the Nazi-era is a big Taboo here and anything that is related with it, is classified as very sensitive by the public and they may not be comfortable talking about it. If you waiting for your bus, just make sure you wait at the right bus stop and the bus will surely stop for you, there is no need to use the "power of your hand".
3) DO NOT JAYWALK OR WALK ON THE BICYCLE LANE
Make sure you follow the traffic rules, especially if you live in Cologne. There are always police who tend to ride their bicycles and they very easily fine pedestrians who violate the law and walk at a red light. Not only that, if you did jaywalk and there are children nearby, you may get yelled directly! So just wait patiently for the light to turn green. A line would usually separate the street into a pedestrian lane and bicycle lane. Do not walk on the bicycle lane as you can once again get yelled at or you may even get injured if the bicycle passes by too fast.
4) BE PUNCTUAL
Zeit ist Geld. Germans are generally very particular about being on time. Therefore, we are expected to arrive on time for any event and especially for an appointment. Showing up on time gives an impression that we respect their valuable time. If you are going to be late or not be able to make it to an appointment or an event , then inform the respective person involved as soon as possible, to avoid any misunderstanding or shortcomings.
5) DUZEN ODER SIEZEN
Whenever you are dealing with someone older or are talking with strangers in formal settings, then by default we are expected to use 'Sie' when referring to the person we are talking with. However, there will also be situations when they themselves directly address you with 'du' as it makes the conversation more casual & friendlier. When in doubt always ask politely prior to starting a conversation.