Believe in the sleeve: Wear this easy midi by day...

Believe in the sleeve: Wear this easy midi by day with a sweater or blazer topper and, for nighttime office party -- voila -- reveal your dazzle; $130 by Ro & De at Anthropologie in Manhasset and Huntington Station. Credit: Anthropologie

Here we go again: it’s the holiday office party. Sometimes it’s dreaded, but mostly it’s a warm, seasonal celebration with colleagues and (remember this) bosses, and you want to look your best. It isn’t hard to amp up an office look for a night of festivities, but (warning! warning!) there is such a thing as going too far.

“It’s almost like your holiday persona should be a more relaxed version of yourself,” says author and TV-personality Clinton Kelly, who was raised in Port Jefferson, starred in TLC’s fashion makeover show “What Not To Wear” and hosted ABC’s “The Chew.” He adds, “no one should be surprised about how you look, wonder if you have an alter ego or be thinking ‘who the heck is that?’ ”

Frock on: Velvet is a holiday staple and this jewel-toned...

Frock on: Velvet is a holiday staple and this jewel-toned tunic style dress with the help of some statement jewelry is subdued enough for the office party but still has holiday spirit. And, it comes in four colors; $130 by Sunday in Brooklyn at Anthropologie. Credit: Anthropologie

So to keep it real, assuming you’re going straight to the party from the office, “nothing says celebration more than sparkle,” says Kelly. “Add some dangly earrings or a stack of bracelets.” Macy’s Roosevelt Field personal stylist Leran Benshar agrees. “This holiday season is all about pizzazz, which can be pulled off easily with statement jewelry.” And you can (and should) go further.

Kelly says, “if you’re wearing a businesslike cotton, button blouse, switch it out for a V-neck silky top and show a bit (emphasis on ‘bit’) of skin in jewel tones such as deep amethyst or emerald.” You can sub that blouse for a bejeweled sweater or camisole, and kick off those sensible, work-worthy shoes and replace them with “a strappy sandal. The shoe sets the tone for the outfit.”

Not a sandal kind of gal? “Bedazzled pumps, can elevate an outfit,” says Benshar. Don’t hold back on tasteful accessories: a glittery belt, bag or even a scarf can do wonders for an outfit. Also, Benshar suggests thinking about a makeup evening update that gives you a glow, “with a touch of holiday sparkle.”

Bag it: A sparkly chain and silvery pouch will add...

Bag it: A sparkly chain and silvery pouch will add luster to your party outfit; $19.99 at H&M. Credit: H&M

 The big "but" is there are definitely things not to wear (to steal a phrase from Kelly’s former show). “Avoid wearing revealing clothing such as plunging necklines, questionable hemlines or sheerness,” says Benshar. Kelly says overexposure is a definite no-no. (Note: slim pencil skirts and smart sheaths are just fine.) He also says to nix the cliché ugly holiday sweater. “If it’s an ugly sweater party then … ok. But, he says, Christmas-themed sweaters are better suited “for a grandmother baking cookies with your grandkids at home. They can be done ironically, of course, but I think the joke is over.”

Wine time: Upgrade a standard suit jacket with a slim-fit...

Wine time: Upgrade a standard suit jacket with a slim-fit velvet sport coat in burgundy; $295 by Bar III at Macy's. Credit: Macy’s

 Remember, what you wear sends a message. “I always want to give caution … maybe you’ve been cultivating a professional image for a long time … you’re dependable, cultured — be careful that you’re not undermining your own brand. People will remember what you did and what you wore the next day.”

So off you go. “Wear your best well-cut suit or dress, swap out the shoes, add a belt, bag, earrings, do a hair toss, check your nails, and you’re out,” says Kelly. Have fun!

Party on, guys

Amping up the holiday fashion is a bit trickier for men, says Clinton Kelly, who starred in TLC’s fashion makeover show, “What Not To Wear.” In many cases, wearing the suit you wore to work is probably appropriate. “Men’s evening wear isn’t that different than day. Maybe switch out your brown shoes and belt for black.” Of course, it depends on the kind of work you do. If you’re a banker, it’s more formal, “if you work in marketing, it’s a more relaxed, fun vibe,” he adds.

Macy’s Roosevelt Field personal stylist Leran Benshar thinks fellas can go a little further. “A perfect holiday outfit can be put together with a statement blazer and a pocket square.” That could work for Kelly, himself, who says he might wear “a wine-colored jacket or a tuxedo jacket with jeans.” That’s a matter of personal taste and, of course, the environment.

A few things to avoid? “T-shirts, sneakers and distressed jeans,” says Benshar. Also, avoid a Santa Clausian red sweater vest. "A guy can look silly."