Here are some decent tutorial videos on how to scratch with vinyl.
The same principal matters with cdj's with regards to crossfading etc.
How to perform "the flare" scratch:
How to "stab" scratch:
The "chirp" scratch:
Crossfader holding tips:
I found some other decent links to setting up final scratch and serato scratch i'll post up as well as links to samples you can use with your cdjs & laptop.