Tip and the bill split between people.
In a restaurant 10% of the bill is usual and good service earns 15%. In a cafe or bar people more often just round the total up. A tip is not compulsory and is not in the bill, unless a service charge is stated for a large party.
Yes — in Latvia a tip is taken from the bill total with value added tax already in it, because that is the figure printed on the receipt. In practice the difference is small: on a hundred-euro bill it comes to a few cents.
Add the tip first and only then divide by the number of people, or everyone pays a different percentage. An 84-euro bill with a 10% tip is 92.40, which across four people is 23.10 each — usually rounded up to 23.50.
Cash reaches the server immediately and in full, while a card tip goes through the venue's till and the way it is shared out differs from place to place. If you have no cash, a card tip is still better than none.