How can i do my hair like Serena on gossip girl?

I want to get my hair looking really pretty and wavy like serena on gossip girl. i like the way she does it normally how it has a lot of volume....also i liked how she did it for the snowflake ball on the last episode of gossip girl. how can i do my hair like that?
http://evilbeetgossip.film.com/wp-content/uploads/2007/10/blake_lively.jpg
http://www.cwtv.com/photos/gossip-girl/005335901ae
http://www.cwtv.com/photos/gossip-girl/00532240910
this next one is at the snow flake ball....
http://www.cwtv.com/photos/gossip-girl/00532290246