ATMs widely available. Credit/debit cards widely accepted, but bring emergency cash reserves.
Hotels €1 per bag is standard. It's also nice to leave a little cash for the room cleaners, say €1 or €2 per day.
Restaurants Restaurant bills always include Bedienung (service charge), but most people add 5% or 10% unless the service was truly abhorrent.
Bars About 5%, rounded to nearest euro. For table service, tip as for restaurants.
Taxis About 10%, rounded to the nearest euro.
Toilet attendants Loose change.