Dave Ramsey has a great system for budgeting ( click here)
Make an envelope for all your monthly budgets.
Then write down how much the budget is. If you budget $400 a month on groceries then write that on the envelope. Thats all you are to spend.
Dave and I both agree its better to be a cash person, but if you must use debit cards use play money in your envelope system. This helps you visually keep track of your money. And you become more conscious of your spending.