[majewsky]

(I'm German. This is my personal stance.)

Charging a tip for to-go items is preposterous. When dining in, I will indeed tip, usually by rounding up to the next 5 or 10 euro increment for a group meal, or to the next 1 or 2 euro increment for single meals (e.g. during lunch hours near the office). But this is only if the service is actually good. If a restaurant makes me wait more than 30 minutes for a quick lunch, they will be paid exactly the amount posted on the menu.