💵Where to give?💵
In Europe, USA, most South American countries, UAE, Israel, Vietnam, Thailand and other countries. The list is big enough

💵Where is it not accepted?💵
In China, tipping is prohibited by the law of the country. Waiters and hotel workers can even be fired if they are seen accepting gratitude from tourists.
In Japan, tipping is almost like insulting someone. But there are exceptions. You can express your gratitude to, say, a guide or a personal driver. Money must be put in a clean white envelope


💵How much to leave?💵
10% Russia, most countries in Europe and the world.
15-20% USA. If this is not done, for example, in a restaurant, you can even run into insults and showdowns with a showdown. The waiter can catch up with you on the street and demand the money due to him.

💵To whom?💵
Waiters. If you liked the service, the food and the restaurant in general.
Porters. A small tip as a thank you ($1 or 1 euro).
Maid in hotels. If you want your room to be cleaned cleanly, and the bath not washed with a toilet brush, leave 1-2 euros / $ per day. If you made a big mess, leave a little more.