If you don't have any cc debt, you can do a few things. I set up a 2d checking account at my bank online. I use a Costco American Exp card because they have a pretty good cash back thing (since I have a Costco membership, this card has no other fees, unlike many AX cards). Whenever I use it, I immediately go online and transfer the charged amount from my checking to the 2d account. When the bill comes due, the money is sitting there, already deducted from my checking and ready to pay the card.
Again, the trick is discipline. You MUST cover the charge NOW, not next month. If you can't cover it, don't buy it.
