Your hair extension appointment ends. You've been sitting in the chair for two hours while your stylist has been carefully installing your brand new hair extensions. Not only did she wash and clarify your hair before installing, but she took the time to blend and style your hair after she was done to make sure your new hair looks completely natural.

Now it’s time to pay her, and you’re wondering how much to tip.

In the U.S., it is customary to tip 10% to 20% of the cost of your service. That means that if your service costs $200, then a 20% tip would be $40. But it isn’t always such a hard and fast rule. The more pleased you are with the service, the more you tip.

Stylists do usually expect to be tipped, and they expect the tip to reflect the quality of the service. If they get a big tip, they know that they provided an amazing, over-the-top experience. A tiny tips sends the message that there was something seriously lacking.

Most stylists agree that 20% of the total bill is an acceptable tip, although many appreciate whatever their clients can give. One stylist said that when tips in her salon were dwindling, they posted a tipping chart to help clients figure out how to calculate tips. Tips skyrocketed because many just weren't aware tipping was expected.

So next time you head to the salon, consider tipping your stylist. Unlike a waiter, she’s spending all of her time working on you. And if you like her work, you want to show your appreciation.