Know before you go. . .
• Service in Berlin is generally okay, but when it’s bad it makes nonchalant Parisians look positively proactive. You’re likely to be the victim of the occasional delay, an arrogant waiter/waitress, or even a scathing glare, but don’t take it personally. That’s the Berlin way.
• Berliners, like all Germans, take their rules seriously, especially things like jaywalking and recycling. Dirtying the streets or crossing at a red light is likely to draw stern looks or even public admonitions.
• On the plus side, Berliners are generally very tolerant and ‘anything goes’ – an attitude that is perhaps most evident in the city’s nightlife, where bars usually close late or when the last guest leaves, and where even indoors There is a palpable lack of tension in the air in the early morning hours.
• In some bars and clubs, a deposit (Deposit) is added to your bottle or glass (between €0.20 and €1/18p to 90p) which is refunded when you return it to the bar. Sometimes you also get a token, which you give back at the end to claim back your deposit.
• Public transport in Berlin works according to an honesty system. There are no barriers at train, tram or bus stations, but tube inspectors will fine you up to €60 (£54) on the spot if they catch you without a ticket. Make sure your ticket is also validated (stamped) before boarding a train (usually there are validators next to the ticket vendor).
• Service is sometimes included in bills, but it is common practice to round up snacks and drinks to the nearest euro or leave a slightly larger tip for meals and larger bills.
https://www.telegraph.co.uk/travel/destinations/europe/germany/berlin/articles/berlin-travel-guide/ An expert guide to Berlin