Here are some ways to attack a zone. I didn't realise there are so many ways to attack a zone until I stopped to count them. Anyone got more?
1. Sneak in and pivot through
The poppers step just inside the wall or cup, lean forward to receive a short pass (less than 1 metre), and pivot past a defender to throw to a teammate. The disc is not thrown through the cup - it is carried through by a legal pivot step of the popper. This requires footwork not used anywhere else in ultimate, so it takes specific practice.
2. Stand in space
Poppers stand behind the cup or wall in space. If the wing defenders are kept preoccupied, at least 1 of the 2 poppers should be free enough. The handler throws a hammer, blade or scoober to the open popper.
3. Decoy runs to make gaps
One popper moves through the cup to move a defender. The handler throws through the gap they leave to the other popper, who has positioned themselves where they think the gap will appear.
4. Flood the weak side
Position a handler on the opposite side of the field to the disc, and have 2 poppers nearby. Leave the handler with the disc all alone with 4 defenders near him/her. When the disc is swung with a hammer or dump-swing, the poppers are ready to give-go, as the disc should arrive before the cup, clam or wall arrives. Frisbees are faster than feet.
5. Flood deep and hammer
Put 3 or 4 players deep, each trying to draw a defender. One offensive player should be left open for a hammer or blade.
6. Dump and swing until a wing is open
This is the status-quo. It is simple and so is usually the first tactic taught on zone offense. It uses the assumption that "the cup will get tired and slow down and we can then pass up the wing, before we make a mistake". This assumption is usually false in beginner and intermediate ultimate. My reasoning: if you throw just 7 passes sideways, each of which is 90% safe, you are more likely to turn it over than not. And you haven't even gone forward towards the goal. And isn't that the aim of offense?