IT is usual when visiting restaurants/bistros/cafés, that the customer will study the bill to see whether a service charge is included. Some establishments claim that the charge, where included, will be shared out between their staff, but it is known that this can be far from the truth. 
So customers sometimes make sure, on receiving good service from a waiter, they give a tip in reward of that service. 
Hair stylists really appreciate that recognition of a grateful client saying thank you in what is one of the lowest paid of occupations. 
Taxi drivers will sometimes be given a tip, especially if they have gone to the trouble of assisting with heavy shopping or luggage, but can be kept back if no help is offered.
But in bringing this to your readers’ attention I would like them to think of the many services brought to their doors that they may take for granted by many who are not highly paid and usually carried out in all weathers throughout the year. 
The practice of the Christmas Box has long been forgotten by many and indeed is unknown to perhaps younger householders. 
My mother, a single parent, always gave what was known as a Christmas Box to our postie, to our refuse collectors, paper girl/boy, milkman, and remembering particularly our vegetable trader known as The Potato Man who had fought in the war. 
So, if you think about the services we take for granted, perhaps this old practice of the Christmas Box might be something to consider in these days when so many have fallen behind in what may be called a living wage. 
More importantly, this could be a big thank you for appreciating the services we are given straight to our doors. 
Not necessarily large amounts, but I can assure you that recipients appreciate an acknowledgement of the difficult work they undertake for us. Happy Christmas. 
Dona Nobis Pacem.