I worked for years as a waitress - and thought I would sling hash until I crept into my grave.

As a result, I'm a highly scrupulous tipper.

My husband insists I'm cheap when we dine out and don't leave 20 percent, even for terrible service. Like the time when the hungover hipster forgot to put in our breakfast order. An hour and a half later, we got our eggs, and she got her next tattoo.

Which leads us to holiday tipping, and what's appropriate.

Here's a handy-dandy guide - culled from various etiquette authorities - about standard tips at the holidays and year-end 2014, for service folks from pet groomers to mail carriers to housecleaners.

Who do we tip? The most common receivers are child-care providers (babysitters, nannies, and day-care workers), those who help us care for our homes (housekeepers, landscapers, and handymen), and those who help us care for our persons (hairstylists, manicurists, and personal trainers).

Sadly, only 7 percent of us tip caregivers for seniors, according to statistics from Care.com, based in Waltham, Mass.

Cash is king. No big surprise here. Gift cards rank next as the most popular, and if you can't afford either, baked goods never hurt.

Care.com's October survey of almost 1,300 members showed 45 percent tip with gift cards/certificates, 22 percent with homemade food, and 17 percent with wine or other alcohol. Yes!

In many cases, tipping is straightforward, usually an amount equal to the cost of one service, or one to two weeks' pay for live-in caretakers such as nannies and home health-care aides.

Hand-delivery, please. When possible, deliver your gift in person and accompanied by a handwritten card. This is an extra: Fresh, crisp bills are ideal.

Gifts should be delivered on or before Dec. 25, but may be given whenever you have contact with the person during the holiday season.

Why tip in person?

"If you are hand-delivering the tip, you can say something to the person as well, such as, 'I appreciate you and all you've done throughout the year,' " advises Jacqueline Whitmore, author and founder of the Protocol School of Palm Beach.

Schoolteachers deserve all you can give for acting as overlords to our little monsters. A gift card for Target or Staples or a school-supplies store is a perfect holiday thanks from you and your children.

"A lot of teachers pay for supplies throughout the year. It's nice to give them something they can use," Whitmore says.

Regifting: Discuss. About 30 percent of people regift when it comes to holiday tips. But we should make sure the gift is something the recipient needs or wants.

Etiquette experts say regifting is "certainly OK, as long as you don't regift in the same social circles," Whitmore adds.

Translation: Aunt Edna gave you a sweater? Don't give it to someone Aunt Edna will see wearing it.

"Label it and write down who gave it to you, and who may want or need it."

The tips stop here. Doctors, physical therapists, and veterinarians don't receive holiday tips.

Still, Whitmore says, "I like to take cookies to the staff, or if they're looking for supplies like towels, blankets, or food for shelter animals, that's perfect."

Whitmore knows tipping isn't for everyone, every year. If you can't afford to tip more than a few people, "it can be something small."

Personally, she says, she'll be tipping her manicurist, hairdresser, mail carrier, and housekeeper. "She comes every three weeks, so I'd say usually I would tip a one-time cleaning. That's standard."

When Whitmore doesn't have the full amount of money? "One year, I gave her some crystal glasses and a smaller tip."

Her dog groomer may not receive the entire price of a service, "because I have two dogs."

Favorite go-to tips are coffee- or tea-shop gift cards, she says.

Who doesn't love a latte?

Tipping Points

Pet trainer Cost of 1 session

Babysitter Average evening pay and small gift

Barber, hairdresser, colorist   Cost of 1 session

Regular bartender  $20-$40

Building superintendent, doorman or janitor    $25-$100

Regular barista  $10-$20

Day care staffers  $25 to $50 and small gift

Dog walker 1 week's pay

Dry cleaning delivery  $10-$20

Elevator operator  $10-$40

Garbage collector  $20-$30

Regular gas pump attendant   $10-$20

Handyman $15-$50

Housekeeper Cost of 1 session or small gift for infrequent service.

Child's coach Small gift from your kids.

Nanny 1-2 week's pay and a gift.

Newspaper carrier  $10-$20.

Regular parking attendant $10-$20.

Senior care aide  $25-$100.

215-854-2808

@erinarvedlund