First, the bottom line:

How much should I tip my hairstylist during the holidays?

The general rule is to double the 15 to 20 percent you usually give, says colorist Sharon Dorram-Krause of Sharon Dorram Color at Sally Hershberger Uptown salon in New York City.

But what if I see my stylist or aesthetician only two or three times a year?

"If you don't consider yourself a regular, you're not expected to give a holiday tip," says Kimberly Knight, a massage therapist at the Elizabeth Arden Red Door Spas in New York City.

Can I give a gift instead of money?

Baked goods, cashmere, keys to the yacht—the people we interviewed always welcome such thoughtfulness. "I think gifts are more special than money," says hairstylist Ted Gibson of Ted Gibson Salon in New York City. Spend about the same amount as you would on a monetary tip. (Need some ideas? See The O List.) "I love the CD a client made for me after she heard me complain about my commute," says Marcy Cona, owner of M.C. Hair Consultants in Cuyahoga Falls, Ohio.

Should I give the assistant a tip or gift?

Most assistants are paid minimum wage, so it's especially nice to give them something. If you usually have a different assistant, send gourmet treats that everyone can share.

What if I don't have a December appointment?

"Then you're off the hook!" says hairstylist Harry Josh of Serge Normant at John Frieda salon in Los Angeles.