Back in 1916, a curmudgeonly book titled “The Itching Palm” predicted that the practice of tipping would one day come to a well-deserved end. Almost a century later, tipping not only lives on but also thrives, especially during the holiday season.

The traditional list of holiday tip recipients actually is growing – and the gratuity amounts are increasing. Traditional recipients, such as hairdressers, newspaper carriers and child care providers, have been joined by an ever-expanding cadre, including fitness trainers, spa attendants, dog walkers and elder-care workers.

Last year, Americans tipped an estimated $26 billion.

The Consumer Reports’ National Research Center recently asked a representative U.S. sample of more than 1,800 people what they gave last holiday season. Good news for those on the receiving end: Compared with a similar survey last year, tips were up about $5 apiece in many instances.

Who gets tipped and the amount can vary by region. For example, while it may be customary for parents to tip their child’s school-bus driver in New York, it’s not expected in Colorado. Therefore, when people move to a new place, it’s a good idea to ask neighbors or co-workers about what’s customary.

Despite the regional variations, the experts interviewed by Consumer Reports were fairly uniform in their tipping advice:

¢ Match one week/session. If the person is not on our list and provides service weekly, give the equivalent of one week’s pay. For instance, if your dog walker charges $75 a week, give her a $75 tip.

¢ Use gift cards with care. The cards are popular as tips because they are widely available and are graceful substitutes for cash. But stay away from the bank-issued variety, which often have fees and expiration dates.

¢ Know the boss’ rules. Mail carriers aren’t supposed to accept cash or gift cards that can be exchanged for cash. They can accept noncash gifts worth $20 or less. For teachers, check with the school district’s office or parent-teacher association. In Lawrence public schools, policy discourages teachers from accepting cash gifts. Indeed, the CR survey found that while 59 percent of respondents tipped a child’s teacher, only 2 percent used cash. Instead, try movie-ticket coupons or join with other parents to buy a gift certificate for a local shop.

¢ Keep it crisp. If you’re giving cash, try to get to the bank for new bills. A thank-you note goes a long way, too.