Parties can be perfect meeting places for potential new dates. You'll probably be dressed to the nines and looking gorgeous, and there's usually some connection between the person you like the look of and the host or hostess, so it's easy to make some enquiries before you make an approach.
Starting a conversation can be easy too: "How do you know (the host or hostess)?", "What's the punch like?", "Would you like an olive?". However, before you make a move, do make an effort to find out if they're already attached; the last thing you want to do is to ruin your friend's party because someone's jealous partner decides to pour the contents of the punchbowl over you ...