The holiday season is upon us and that can only mean one thing - holiday office parties.

As the fetes start to roll out, many are left wondering what (and what not) to wear to their office parties this year. And this is a serious matter, as many are flustered by the thought of mingling with coworkers outside of the office space. Having to worry about fashion is just an added stress.

Here are some tips on what to wear, and what not to wear, to your holiday office party this year.

What to Wear

For a holiday office party, classy is the key phrase to keep in mind. Though simple and sophisticated are always welcome, a bit of pizazz will certainly not hurt either. Since it is the holidays, it is perfectly acceptable to wear something with a little more oomph to it.

This season some of the biggest trends are sparkle, lace, metallics and red. There are ways to make each of these looks work-oriented.

For instance, when wearing something sparkly - such as a gold sequined top or glittering pumps - make sure to keep the rest of your outfit simple. Opt for black trousers instead of a short black skirt with the top, or a white sweater and cigarette pants with the pumps.

When wearing lace, something like a lace dress or lace tights, make sure that you balance it as well. A lace dress is a beautiful option, so long as the cut is long and the fit is not skin-tight. Lace tights are just as lovely, but pair them with a knee-length skirt and modest top to keep the sexy at a minimum.

Keep in mind the location. If you are going to a party in the office, you are not required to dress as fancy as you would be for a formal party at a separate venue. If you are going to the party straight from work, you can bring along some accessories to add to your outfit at the end of the day instead of being glitzed up from 9 to 5.

What NOT to Wear

What NOT to wear might be more important than what to wear. Holiday office parties are just that, parties; but employees must be careful to never overstep the boundaries of professionalism.

Woman should never wear plunging necklines that reveal even an inch cleavage. Do not wear mini skirts or bandage dresses or anything sheer, either. It is important to remember that even though this is a social event, you will be surround by people you work with -- and people who you will have to face bright and early the next day.

Do not reach for the Christmas-themed sweater (unless you are going to an Ugly Sweater Party) as this will come off as tastelessly goofy. It is also best not to add on any holiday-themed accessories to even the most prim ensembles, i.e. reindeer antlers or garland.

It is important to remember that this is a special gathering that your employers have went out of their way to plan. Make sure to never dress too casual so as to display nonchalance.

Check out the slideshow, complete with some perfect holiday office party options. Leave any suggestions or feedback in the comments section below.