Warmup exercise in a box. Disc moves in a U-form at the outside, players fill the open spaces while they receive or give a pass. Make the box as big or as small as you want.
If the other team set up their defense with a "sandwich" at the back then it will look like this. 7 will mark the break side, and 6 the open side. They will take any runners to that side. To beat this then do the following.