Notice that the first word in "business holiday party" is business. Your goal is to get a business opportunity, not "win the party." Here’s how:
Leave the cell phone, Android, iPad, Blackberry, iPad, iPhone, iMac, iDon'tCare in the car. No one cares how fast you can move your thumbs when your business contact is sizing you up. Your text can wait -- you are really not that important -- if you were, you would have an administrative assistant who handles your routine communication.
Bring your own name badge. Yes this sounds a little weird, but if the adhesive or clamp on the back of your name badge has ever ruined your clothes you know what I mean. Your name sloppily handwritten with a heavy black sharpie does not make a good first impression either.
My mom always said to stay away from religion, cars and politics when trying to be a good conversationalist. My mother was always right. Quoting Rush Limbaugh or Rachel Maddow will not win you many friends.
Watch the drinks -- no one does business with the life of the party, they are merely amused by them. If the party serves cocktails only, drink ginger ale or club soda and let 'em wonder what's really in your glass.
Unless you are Will Ferrell, don't try to be funny -- you are at a business meeting trying to make a professional connection that can help grow your business.
Arrive early and leave early. The host (or your desired target) will be accessible early in the evening and you will have access to a decision maker before it gets crowded.
Forget what your mother told you and talk to strangers. Engage the first person you make eye contact with in a conversation and see where it takes you. There’s nothing worse than hovering around Mr./Ms. Big waiting to lay your witty line on them, along with everyone else.
As for eye contact, don't let your eyes wander around the room looking for a "better" contact -- have the courtesy to give undivided attention to the person you are engaged with. Excuse yourself politely if the conversation is strained or they are not a suitable target for business.
Be a good listener -- people are often more impressed and will open up when you pay attention to what they have to say (feign attention if they are boring the bejesus out of you).
If an opportunity presents itself, wait until your conversation ends then find a quiet place to write down as many details from your conversation as you can on the back of the person’s business card or an index card. Yes, it sounds crazy but it works. If you do not recap the conversation at that moment you will mess it up the next morning when you try to reconstruct the conversation -- I guarantee it!
While you are at it, try to write down the name of folks you chatted with even if you didn't get their business card.
Drop all contacts a handwritten note (not an email) the next day and include your business card -- assume they lost or pitched it “by mistake.”