How do you tear/destroy/distress jeans?

I absolutely LOVE the jeans ashley tisdale wears in her music video, Its Alright, It's Ok (not the white ones) They are sort of ripped on the knees, and i don't know the word for it but its where there is those white strings from the inside of the jeans. Heres the link:
http://www.youtube.com/watch?v=On_ZPiDEqkA
They start showing them on :42
I dont want them over done and i dont like holes, just the string things. THanks

take a razor blade and run it along the jeans, against the weave of the denim
the edge of scissors will also work

answer mine?
http://answers.yahoo.com/question/index;_ylt=AmAqZOQYjXx2VQD1uOALAGHsy6IX;_ylv=3?qid=20091018142006AAu5F09

Missa's Monthly DIY Video: Distressed Jeans