it's all about the shoulder and hip movement. The ball is secondary, you just gotta show 'em it. I've made people fall quite often without the ball tryina break free.
On the crossover one of the most underrated moves is the standard between the legs inside out, followed immediately by outside-in, something like this:
http://www.youtube.com/watch?v=TmUyuvqCth8
at 6:42.
Just push your front foot up and lean forward a bit on the move, and you can sell it pretty well.