Tips are so much a part of our lives that they can be included in some bills or calculated thanks to free smartphone apps.
But once you get beyond the obvious people to tip a waiter, a hairdresser, a cab driver, a bellman; there can be that gray area of who should get a simple thank you and who should get some cash.
CNN Money has a new list of some professions you may not tip now--but may want to consider the next time.
Starting with exterminators--one says about one in five of his customers tips about $10 to $20, more if they have big bug problems to be solved.
The co-author of Emily Post's Etiquette, 18th edition says it's ok to ask dry cleaners if you can leave a tip--especially if they've tackled a tough stain.
Salon services that go beyond hair could be good places to tip--especially for makeup and tanning. Standard tips range from 15 to 20 percent.
And the article says it might be good to tip your cable guy, pointing out that even though some large providers like Comcast ban workers from accepting gifts, non-monetary tips like moving furniture away from the wall or cable outlet can go a long way.
Another etiquette expert says, we tip to show respect to a service provider--saying when in doubt about tipping...do so.