Got a terrible Christmas gift? Here's what an etiquette expert suggests you should do to avoid hurting anyone's feelings.

• Receiving a Christmas gift you hate doesn't have to be a burden.
• Asking politely if there's an option for an exchange is fine, an etiquette expert told CNBC.

Did your stomach drop after seeing the Christmas gift you got from a beloved family member or friend? Here's what you can do to avoid hurting their feelings, according to an expert.

First things first, be honest. If somebody gave you a kitchen appliance you know you'll never use or a piece of clothing that just doesn't fit, asking politely if there's an option for an exchange is considered reasonable.

"If it's, say, the shirt that doesn't fit, you might say, 'Oh my gosh, this is lovely. But I have to tell you — would you mind if I switched it for the right size?'" Diane Gottsman, the founder of the Protocol School of Texas, a company that offers services in professional etiquette training, told CNBC.

If that oversized pair of pants you got didn't come with a return receipt, there's a few things you can do to ensure it doesn't take up unwanted space in your household.

If you're a coffee drinker who received a tea kit, Gottman says donating it to charity can be the right thing to do.

Another option is to regift the present. If you do this, Gottsman said being transparent about where you got the gift — and showing thoughtfulness — to the person receiving the gift is a matter of common decency.

"If you regift it, you need to be honest, and say, 'listen, I received a tea kettle, and I know you love tea. I would like for you to have it if you think you could use it,'" Gottsman told CNBC.

If you decide to recycle the gift, Gottsman suggests handing it to somebody outside of the original gift giver's friend group. That way, feelings won't be hurt if the original gift giver finds out.

"I always say, regift in another city," Gottsman said.

And if a person you don't know very well gave you the gift, saying a simple "thank you" should be enough, Gottsman said.

After all, it's not the gift that matters — it's the intention behind it.

"You're thanking them for the effort. You're not thanking them for the gift," Gottsman said. "The gift is secondary. It's the thought and the effort and the love that counts."