You might think you look delightful, but your fellow holiday revelers will find you frightful in a get-up like this. Photo: Yoshikazu Tsuno, AFP/Getty Images

It's holiday party season, and the social calendar is filling up fast. Ugly Christmas sweaters, red velvet dresses with fluffy white trim and eye-popping cleavage? All things to avoid as you contemplate your party wardrobes.

"A Christmas party is not a costume party unless the invitation says dress like an elf or Mrs. Claus," Clinton Kelly, co-host of TLC's "What Not to Wear" and author of "Oh No She Didn't," tells StyleList.

So, assuming your upcoming soirees do not include odes to Rudolph or drape-yourself-in-tinsel themes, we asked two of our favorite TV style show hosts – Kelly and Danielle Fishel, host of "The Dish" to advise us on how not to dress for holiday parties.

1. Avoid the Christmas Sweater!
"I really don't know why people think that Christmas sweaters are cute," Kelly says. "If you're a kindergarten teacher, I kind of get it. If you're baking cookies with your grandkids, I kind of get it. But the second you leave the house in a Christmas sweater, it's like, ooh, just add another decade to your age. A holiday sweater turns you into a total joke and makes you look a minimum of 10 years older -- and it's very rare that I meet a woman who wants to look older."

Clinton Kelly wants you to just say no to Christmas sweaters. Photo: Mark Von Holden, Getty Images for NYC & Company

2. Red and Green Is Great for a Tree...
"Bright Christmas-y red and bright Christmas-y green -- is just a little bit too obvious, a little too cliché," Kelly says. "If you want to look more sophisticated, it's probably a better idea to look for richer colors; things like jewel tones are great, deeper burgundies, anything in the wine family is nice, merlot, that kind of thing. Especially be careful of wearing red and green together."

3. Be Yourself
"Wear something that fits your personality, no matter what that is," Fishel says. "A holiday party is not the time to try out a new persona. If you're colorful, wear something that shows that, and if you're more reserved, reflect that in you outfit, as well."

4. If You're Going to Wear a L.B.D., Dress It Up
"A plain L.B.D. is not really enough to carry you through a holiday party," says Kelly. "You need to make your little black dress special during the holidays, whether that's through an amazing pair of shoes or really kick-ass jewelry."

Danielle Fishel says ease up on the sexy at your office holiday party. Photo: The Style Network

5. Wear Something Comfortable
"If the outfit you want to wear is only flattering when you're standing, facing one direction, pick something else," Fishel advises. "When you wear an outfit you feel good in no matter what the seating arrangements are, or what the lighting is, you feel confident. And confidence is sexy."

6. Jingling Jewelry Is a No-No
"I don't think you should wear anything that jingles on purpose," Kelly says. "Sometimes I see these earrings that look like Christmas lights or bells. Anything battery operated is probably best left to the privacy of your own home."

7. Dress Warm, It's Winter After All!
"If it's cold the night of your holiday soiree, dress for the weather," Fishel says. "Short, sleeveless dresses with open-toed shoes look silly when it's 35 degrees outside."

8. Overly Sexy Outfits Aren't For Office Parties
"You might be an incredible attorney, but if you show up showing a lot of cleavage and a lot of leg, it's really hard for people to erase that image from their mind the next time you're in the courtroom," says Kelly. "Keep skirts to the knees, keep the cleavage to a minimum. I have a rule of thumb for professional environments: You can show chest but not breast."

Fishel agrees that wearing anything both low-cut and short to the office party is a no-no. "You've worked hard for the reputation you have at work; don't blow it by dressing the part of office skank," she says.

Seeking more style advice? Here's how to wear herringbone.