The relationships you form in a salon can be the most intimate in your life. Who else but your hairdresser can examine your gray or damaged hair with such practical indifference? As for your bikini waxer, she may not be your friend, but she is your... bikini waxer. It doesn't get much closer than that. If you're not sure how much to tip these essential people in your lives, you're not alone. We asked Tahnee Seiler, student services coach at the Aveda Institute, and Elie Camoro, a top stylist at Frederic Fekkai, to tell us the right way to tip. They also share some customers' faux pas.

How Much Should You Tip?

What customers do: In Aveda's informal poll, the lowest tip was 10 percent and the highest was 25 percent, but most women said they stick to 20. In and around big cities, the percentage was more generous, even though the services cost more. Women with supershort hair, which they get cut and colored every four to six weeks, don't always give a huge tip because their annual beauty bill is so high to begin with. Stylists in some small-town beauty shops, however, report 15 percent as the norm. Those who work in mall or drop-in hair salons, and are less likely to have a loyal clientele, sometimes get tips of even less.

What salon staff wants you to do: Start from 20 percent to be fair. Young mothers up the ante if their preschoolers are in on the haircut. If you arrive late or have a toddler with you, you should increase your tip. Other reasons to tip more: if the salon squeezes you in at the last moment, your styling includes a shoulder massage, or your manicure includes a hand massage. The bottom line: If you like your hairstylist, tip at least 20 percent. It helps build relations with the salon and is especially helpful in procuring a last-minute appointment.