"It rarely happens because we talk a lot as we go, but if/when it does, I offer to redo the service or provide them with a discount on the service. Most of all, I listen and make sure their concerns are heard."

Unfortunately, sometimes you just can't seem to get it right. Some customers will just never be satisfied, no matter how hard you try. Give an example of a time when you had a hard time meeting the customer's needs. Be sure to talk about what you did to remedy the situation and what you learned from it. Here's an example to get you thinking in the right direction:

"I had a client who wanted to color her hair much darker than her natural color. I advised her to stay with warmer tones since it would complement her eyes and skin tone. She insisted on going more on the ashy side, so I gave her exactly what she requested. In the end she wasn't satisfied. I did a color correction towards what I had originally recommended, but I could tell she was frustrated about the situation. I gave her a complimentary blowout in return, and learned that sometimes it's better to use your best judgement, even if a customer wants something different."

"I had a client who wanted to color her hair much darker than her natural color. I advised her to stay with warmer tones since it would complement her eyes and skin tone. She insisted on going more on the ashy side, so I gave her exactly what she requested. In the end she wasn't satisfied. I did a color correction towards what I had originally recommended, but I could tell she was frustrated about the situation. I gave her a complimentary blowout in return, and learned that sometimes it's better to use your best judgement, even if a customer wants something different."