Guy Kawasaki has a good list of items from Susan RoAnne to consider before you go out to a ‘smoozing event’. 

I like the item ‘#2 Prepare For The Event’ a lot.  I’ve had a very
good recent experience doing something similar a couple of months back.

Another suggestion is to listen to Manager-Tool’s podcast entitled "How to Politely Become Part of a Group." 

I have also used the recommendations in this podcast to have an
overall better social experience where previously I would have felt out
of place.