Big head mode:
Pause game play, then hold Select and press , , , , . Release 
Select. Then, hold  again and press then press , , , , . 

All Dream Keys:
Pause game play at the house hub, then hold  and press  , , 
, . 

All Winks:
Pause game play at the house hub, then hold  and press , , 
(3). 

Full cogs:
Pause game play, then hold  and press , , , , . 

Restore moons:
Pause game play, then hold  and press , , , , . 

Restore Zzzs:
Pause game play, then hold  and press , , , , .