If you're spending $50 or more at Spotlight, be sure to buy the Get Creative magazine for 99 cents. On a $50 buy that's a (further?) discount of nearly 20 per cent. It's generally a pretty poor magazine, but has a voucher on the back for a $10 discount on a spend of $50 or more. The discount can be used in the same transaction as purchasing the magazine, and can be stacked with other offers and discounts, provided your final spend before applying the $10 discount is $50 or more.
It's for instore use only, not online, and can't be used for payments on existing laybys and I am guessing cannot be used for special orders.
Great OzBargain hack OP, thanks!