'Tis the season to (still) act professionally

December heralds the season of Christmas trees, singing carols, fake snow, Secret Santas...and holiday office parties. These parties elicit a number of reactions from employees, ranging from joy at free food and adult beverages being offered to dread and annoyance at the notion of spending an evening with your effing boss and your effing coworkers. In my opinion, office parties are generally worth going to as long as you keep a few things in mind:

1. You're still at work. No matter what everyone's wearing, no matter how much alcohol is being served, no matter if your boss is dancing around with a lampshade on his/her head, remember: it's still a work function. Resist the urge to overimbibe at the open bar or freakdance with the cute new hire--you're still going to have to be on your best behavior (or at least on your work behavior). If anyone in charge sees you acting a fool at the office party on Saturday night, it will be remembered on Monday morning.
2. Take the opportunity to talk to people in a non-structured environment. While you are still kinda at work, you're not on the clock. So an office party is a good time to chat with your colleagues about non-work stuff: what do they like to do on the weekends? What are their kids into? Where did they go on vacation this year? What are they doing for the holidays? You likely already know that office parties are a good time to chat up the boss, but it's a good time to chat up other managers in the office, as you never know when you may end up working with them. Further, chatting with coworkers--whether you work with them or not--is a great chance just to get to know them better and develop a better working relationship with them.
3. Have fun or go home. Having zero fun at a party is just about as bad as having way too much fun--they're both inappropriate reactions to the festivities. If your office party has a ridiculous theme--hey everybody, we're doing Hee Haw!--don't feel like you have to play it to the hilt. Just wear a nice outfit that's not formal but doesn't involve khakis. If you don't really want to go but feel like you need to make an appearance, get there right at the beginning, not fashionably late. Stay for a couple of hours and chat up a few people that you really like, then use whatever excuse you feel comfortable with in order to leave--I'm double-booked for parties, I have a migraine, the cat's having kittens, whatever. Say some pleasant goodbyes, go home, and relax, knowing that you're not going to have a hangover tomorrow.