Theres a friend called GOOGLE.se.
"The distinction between "freestyle" and "hacking" is in the eye of the beholder. Almost all advanced freestylers practice and play in a circle, with the same rules everyone is familiar with:
- courtesy tosses to start the rally, (b)
- no hands, (c)
- trying to make sure the footbag gets passed to every player in the circle. (Advanced players tend to always pass the hacky sack in a specific direction to players around the circle so that they dont skip anyone, although even in circles of top players, this is not always possible.)"