There are generally two schools of thought for controlling your spending. The first is a cash envelope system, where your monthly budgeted amount for every category is placed in an envelope with the category written on it. The second is to use the debit card for everything and track it using money management software.
Strangely enough, I like to use both. Better than that, I have to use both. I have tried to go all one way or the other, and it just doesn't work.
Our fun money has to be in cash. If I use the debit card for my fun money, I overspend my budget. Without fail. When I have cash only for fun money, I can keep it in check. The sooner I go to the ATM and take out my fun money, the better off my month is budget-wise. (Which reminds me, I need to get November's fun money.)
Everything else - gas, groceries, household expenses - are all on the debt card. I can't imagine carrying that much cash around, not to mention that my husband needs to spend some of that money as well and it's not practical to split that money. We just make sure that the totals don't surpass out budget. Plus, I can track when we spend the money rather than how much we have remaining.
So this is what works for us. It's a little unorthodox, but a lot of what we're doing now is irregular. How do you keep track of your spending - cash or debit? (Presumably, if you're reading this, you don't use credit unless it's for the points.)