I read a few months ago (online somewhere that I can't even remember, so, you know, this is very official and absolutely true) that people who think they have a lot of self-control around food tend to actually eat more junk food/desserts because they buy it and keep it around their house, assuming they can just "say no" with that iron will. Whereas the people who who say, "I can't even have a cookie in the house or I'll scarf it down before it's cooled," eat less because it's just not there. Let us not discuss which category I fall into. There is a reason I buy nothing except canned tomatoes and cheerios, if that gives you a hint.
The same thing is true, of course, for money.
We all like to think we're good at money, using our coupon here, or sending in a rebate form there, but then finding ourselves with the cupboard full of cookies that we are deeply tempted to inhale. I can say no to a lot of things, but show me a pair of shoes or clothing item on clearance (here come my True Confessions too. . .), and I am hard pressed to say no. Because, I can justify it all afternoon long, since it was 75% off, or because it was already on sale AND I had a coupon.
The goal, then, is to empty your money cupboards of cookies and chips and other things you can't resist, and just make it easy on yourself to not spend. Make it so you don't have to decide EVERY SINGLE TIME you open that cupboard to say, "No. No cookies."
My mom mentioned yesterday that she doesn't keep her debit card in her wallet. She doesn't have to decide every single time if she's going to spend or not. That's keeping the cookies and chips out of your cupboard.
I do not go to the grocery store more than once per week. Otherwise, every single trip will cost me an additional $10-15 and kill my budget. I just don't even go through those doors. I can live without any one item for a week. I can go two days without eggs. If I'm out of cereal, I can have oatmeal or toast or a muffin or a smoothie.
Some people use only cash because you can't actually spend cash you don't have, much like you cannot eat cookies that are sitting on the grocery store shelf, miles from your kitchen.
A friend of mine had his credit card numbers saved in Amazon and iTunes so that he could make purchases at either site without having to dig out his wallet. Very convenient. Actually, a little too convenient, he discovered, when he signed up for mint.com and it showed him the previous year's expenditures at each of those vendors. Hundreds and hundreds of dollars at each location. Especially on a site like iTunes, where each song or movie is 99 cents or maybe $3, that means he had clicked the purchase button, literally, hundreds of times. It's just too easy. The same day he saw those numbers on mint.com, he disconnected his credit card from both sites so that he would have to consciously choose to make purchases. (Oh and, yes, I asked permission to share this story - if you share a story about your money habits, I will not link to you and tell in great detail about your horror stories).
It can be hard to identify your own spending temptations. Like my clearance shopping, it's easy to justify; like my friend's iTunes spending, it's such little amounts that you don't have any idea until you see a yearly chart that it's costing you hundreds of dollars. This might be a chance for you to ask your spouse, "what do you see as a money spending trap for me?" (maybe ease the pain of that conversation by offering your own helpful advice to them about what their spending pitfalls are) or to plug your bank accounts in to mint.com and see if there are categories that shock you. And then decide what you can do to get rid of the temptation.
Disconnect the credit card; stay out of the store; take your debit card out of your wallet; call and cancel the catalogs that come to your house. None of those things are worse than the stress of feeling like your finances are out of control. None of those things is harder than retiring with less money than you need to live comfortably. It's worth asking yourself an uncomfortable question now and then doing something about it.
Make it easy on yourself to do what you know you should be doing.