Once you have a good, detailed picture of your monthly spending habits, as well as a prioritized list of needs and wants, you can begin the painful but necessary step of planning your budget. If you find you're losing money and digging the family into debt, your first priority will be to limit spending and start saving. The first saving goal should be an emergency fund.
But long term financial security also involves setting bigger goals with the money you're able to save. Is college on the horizon for your kids? Are you worried about having enough for retirement down the line? Setting concrete goals will not only help you plan for the future, but probably also give you more motivation to stick to a budget. If you can fit short-term goals in, like vacation plans, it will feel great to have these rewards in the not-too-distant future, too.
So, if you're losing money, or not saving enough for your goals, it's time to take a cold, hard look at everything you can cut out of your expenses. Use your prioritized list of needs and wants to help you make difficult decisions.
Consider what you can do to improve your income as well. Can you work overtime? Ask for a raise? Take a second job? If one parent isn't working, taking a full- or part-time job is a possibility.