Eating and drinking is a great way to bond with strangers. Comment upon the delicious cheese dip or wonder aloud (to a specific nearby person) why the cheese dip is radioactive orange, or exchange cheese dip recipes with a fellow cheese enthusiast. If there's no cheese dip, abandon ship! Just kidding. This nifty trick works with all foods.
This is really hard, but it's really important — unless you want everyone to know about your crazy morning shower rituals or how you ate some cake out of the garbage can the other night because it looked good and wasn't covered with gross food or anything. Getting really drunk at a party when you're amongst your BFFs is bad enough, but when you're the girl that came alone and got wasted, you might not get invited back. Or, conversely, you'll get invited back always and it will be your schtick to be the really, really drunk girl and your life will become a downward spiral toward endless boozy nights, unemployment, and depressing solitude. Either way, I don't see good things. But get a tiny bit drunk. You'll seem very go-with-the-flow, and you'll have more fun, duh.
Don't try any of those food tricks, like eating 4,000 saltine crackers in five minutes, or drinking two gallons of milk in 10 seconds. There's no need to be a hero.
If you've eaten a lot of spicy things, make sure to pop some gum before telling a cute guy how much you love the cheese dip. Spicy breath will make people run away. And bring a mirror. You don't want to be a victim of the old spinach-in-the-teeth. And people get so annoyed when you're constantly asking, "Do I have anything in my teeth?!" No! Calm down! You probably don't! Unless you do.
Don't eat all of the food at once. And don't put anything on your plate that is unidentifiable. It will get awkward when it's still on your plate an hour later and everyone's like, "Why did you put that weird thing on your plate? Did you actually think you were going to eat that?" And then they'll start making all these untrue assumptions about your life, like that you eat cake out of garbage cans.
Ask a cute stranger, "Can I get you some punch?" Sure, it's obvious flirting. But the cute stranger will probably be grateful. Even if they aren't interested in you, they might be legitimately thirsty.
Tell someone you like her dress, even if you don't really like her dress. It's OK to lie for the sake of your social life. I'm giving you permission.
Make up a story about how you taught the hostess to ride a two-wheeler. That story is outrageous enough that nobody will think it's true, so they'll think you're funny. Or, at least I'll think you're funny if I'm at that party. That's a funny joke!
Ask everyone how they know the host, and have everyone tell their favorite story about the host. It's never a bad idea to suck up to the person in charge. Maybe he'll be giving away cookies later, or something. Plus, this is a great way to stir up great conversation.
Do your sword swallowing trick. You knew that (or your peacocking abilities) would come in handy sometime!
...Comfortable. If you're pulling at your bra straps or yanking your skirt down the whole time, you won't be able to relax and you won't be able to be yourself and you won't be able to strike up witty banter. And although I never listen to this advice, it's always said that dudes dig a lady in jeans and a white T-shirt. I mean, is that true? Maybe it's worth a try. (Let me know how it goes. I'm sticking to my heels and skirts.)
...That's a conversation piece. If you need an ice breaker, wear one. A piece of jewelry that has a story (it was your great grandmother's, you bought it drunk shopping in Florida...), something that suggests human interaction (a slap bracelet), or a monocle. Hey -- I'd approach someone wearing a monocle.
...Something. Don't go naked. But...
Your outfit should not have pockets. Well, it can have pockets, but don't put your hands there too much. You'll look standoffish and awkward.