It’s that time of year again: time for the office holiday party. Like it or not, you’re probably going because being a no show won’t make you look good. There’s a lot on the line because what happens on this one night can set the course for the rest of your time with this company if not your career.  What do you need to know?

Sharon Schweitzer, an international business etiquette expert, author and the founder of Access to Culture, offers these tips:

• RSVP: Be sure to respond to an invitation with 48 hours, regardless of whether it comes via Evite, email, telephone or traditional methods. As much as you may not wish to attend the office holiday party, you must. Attendance is practically mandatory – failing to go to the annual holiday party sends a negative message. Executives and upper management will take note.

• Don’t Automatically Assume You Can Bring an Extra Guest: Be sure to read the invitation carefully. Know the company policy on guests, or whether the event is ‘Employees Only’ or has a ‘Plus One.’ Discreetly check ahead of time to determine whether spouses or dates are welcome. It can vary by company.

• Dress to Impress: The Holiday Party is one of your few chances to see colleagues outside of the office. Dress up–but do so the right way. The dress code will be printed on the invitation, HR can share wardrobe tips, and so can a trusted colleague. The holiday event, in whatever form it takes, is an extension of the work day, so it’s all business. Choose modest attire that maintains the professional reputation you’ve built. Avoid short skirts, tight clothes, or inappropriate ugly Christmas sweaters.

• Don’t Binge at the Buffet: Eat a small amount of protein before the party to curb your appetite. You were not invited because the hosts thought you were hungry! Be considerate of others and remember your etiquette basics – keep hands clean and avoid a mouth full of hors d’oeuvres. Avoid walking around with a full plate, do not double dip or eat over the chafing dish, and properly discard toothpicks, napkins, and plates.

• Network, Network, Network: This is your chance to converse with senior leaders of the organization with whom you may not typically get much face time. Avoid clinging to your cubby buddy. Instead, meet customers, and new faces from other departments. If you work for a large organization and don’t often see the CEO, introduce yourself, state the department you work in, and shake their hand (keep your beverage in your left hand so your right is dry, and free to shake). These interactions might open doors for future growth opportunities. Thank the hosts, party planners and your superiors when departing. Avoid gossip or talking shop (this is a party, after all!). Skip controversial conversation topics (religion, politics, sex) and keep the mood positive and light. Travel, pets, movies, and books are conversation starters.  At all costs, avoid appearing bored and ready to dash for the door.

• Don’t be Monday’s Gossip: This is probably the most common mistake that executives make during the holiday party. Alcohol and a loose tongue may add up to a regretful Monday morning equation. Consider tea, club soda or water. If you choose to drink, do so responsibly.

• Don’t Clap for Yourself: The CEO may offer a toast during the evening. When the toast is for a colleague, raise your glass at the conclusion of the toast, when the host raises their glass. Do not touch your glass with everyone elses; it is unnecessary and distracting. Pause afterwards and watch. The recipient will most likely reciprocate with a toast. If you have been a star performer, you may be honored with a toast. Stand and accept it gracefully. Refrain from drinking to a toast offered in your honor; this is akin to clapping for yourself. Be sure to stand and make a toast to the person who toasted you, thanking them for the recognition.

• Watch the Clock: Be sure to arrive and leave at appropriate times. Arriving too late shows a lack of appreciation, and overstaying is inconsiderate to the hosts. Arrive within 15-20 minutes of the start time, and leave 30 minutes before the end time.