I liked this tip:
3. Mix up Your Shooting Angles and Focal Lengths
...it can inject a lot of life into party shots if you do mix up your shooting angles and focal lengths at a party. Try some shots from standing up high (get on a chair even to accentuate it - this can be great for group shots) but also get down really low and shoot looking up at kids.
I also liked this one:
11. Take Before and After Shots of the Party
It’s amazing to see how a room (and people) can be transformed in just an hour or two when you have a group of children in it.
I often take a picture of the "after" on Christmas morning - it always makes me think of the movie title, "The Remains of the Day" - not because of the movie, just the phrase. Wrapping paper and ribbons everywhere, empty gift boxes, kids sacked out with new video games, and my husband dozing in the chair. Definitely gives a sense of "whew! Done with the festivities!"