All dreamkeys
Pause the game in the house hub, then hold Select and press Circle, L1, L2, L1, L2.

All winks
Pause the game in the house hub, then hold Select and press Left, Down, Right(3).

Full cogs
Pause the game at any place, then hold Select and press Down, R2, L1, Up, R2.

Restore lives
Pause the game at any place, then hold Select and press L1, Up, Right, L2, Up.

Restore moons
Pause the game at any place, then hold Select and press Up, L2, Left, R2, Left.

Restore Zzz's
Pause the game at any place, then hold Select and press Right, L1, Up, R1, L1.

Big head mode
Pause the game at any place, then hold Select and press L1, Up, Right, L2, Up. Release Select, then hold Select again and press L1, Up, Right, L2, Up.