Cheat Gnome:
While on a lot in Live mode, press L, R, Up, X, R to spawn the Cheat Gnome. The Cheat Gnome appears at different locations, depending on which island you are on. Find the Cheat Gnome, then enter one of the following codes to unlock the corresponding option on the Cheat Gnome. To use the Cheat Gnome, approach it and press X.

All plans – X, R, X, R, X.
All crafting resources – Square, Triangle, R, Down(2), Up.
Maximum current food and resources – Quickly press Square(4), L.