The Frontcross is more difficult than the Backcross, which I can already do. In the Backcross, every ball is thrown from behind across the opposite shoulder and caught in front.
Here's a video of what I was doing this morning.
Video location: http://jimmyjuggler.blogspot.com/2010/01/frontcrosses.html
Or watch it on YouTube:
I find the Frontcross easy to learn, but hard to master. I'm still working on it!