Waiter in a restaurant:  you need to ask for the bill, pay and get change. And then leave the required amount in cash. Don't know how much? Use tip percentage calculator to do the math. 

Well, yes, if the waiter arbitrarily took the change you are waiting for, do not hesitate to demand it.

Beauty salon:  you can deposit the total amount at the reception desk. But it is better to distribute it to those who took part in the process. More than 10% is not left.

Taxi:  you can leave him 5-10%. Nowadays, most services offer to leave a tip directly in the application, so this has become quite easy. By the way, for example, in Greece and Belgium it is not customary to tip taxi drivers.

In a hotel:  tips for the maid or doorman are not required; they can be left according to your mood, depending on your own assessment of the quality of service and the status of the hotel. The concierge, elevator operator, and garbage collector are not given tips.

Refuelers, car washers:  you can tip the gas station attendant and car wash within 10% of the cost of the service. I give it to the gas station attendant so I don’t freeze.

Delivery workers, couriers:  for the delivery of water, food and orders in restaurants - optional, but not more than 10%, and if the delivery was free.

They definitely don’t leave it to:  a flight attendant, a guide, a translator, a chef, a fellow traveler on the train for help with things, a personal trainer, a psychoanalyst, doctors.