Resist buying that "just got to have" item by making it hard to get to your credit card.
Fill a quart freezer bag with water and put your credit card inside and put the bag in your freezer compartment.
When it's frozen, put the quart sized, frozen credit card in a half gallon bag and fill it with
water and put in the very back of your freezer compartment.
Having to go home and dig out the credit card and un-thawing it means you REALLY need the item - or you have no won't power at all!