A tip about tipping
How much is normal? In the U.S., many waiters are heavily underpaid, so they need a relatively high tip to earn their living. In Germany, service charges are included in all restaurant and pub bills. Nonetheless, it is customary to round up prices to the nearest euro, to leave two or three euro or up to 10% if in restaurants.
Normally, one gives it to the waiter or waitress as one pays the bill but leaving it on the table before departing has become more known as customary for foreigners. Bartenders also often expect a small tip.
In the hotel, the service charges on bills is sufficient for most tips, though to tip bellhops, porters and room service about one euro per bag or service is ample. It's also quite widespread in Germany to leave a small tip of around one euro per night for the room-cleaning staff. Whether you tip the desk clerk depends on whether he or she could help with any special service.
Taxi drivers often receive tips of up to five or ten percent of the driving costs. It is only recommendable to give more if one has particularly cumbersome or heavy luggage.