The next step in writing a budget for a family is to draw some hard lines between what the family needs and what it merely wants. This isn't as easy as it might seem, and each family will have to decide this on its own. Take food, which is in itself a necessity. But what kind of diet is the family willing to settle for -- especially when it might mean sacrificing what's considered the healthiest options? The first step is, of course, to eliminate unhealthy food items. But after that, it might be difficult to juggle the health benefits versus the price.
Even clothes can be a judgment call. Working adults might require a polished wardrobe for their career needs. And most parents don't want to make their children uncomfortable by sending them to school wearing old or tattered clothes.
Internet access has arguably become a necessity for nearly every family nowadays. Work and school needs might require it. But do you need high speed Internet? You might be able to find a cheaper deal that still reaches your needs.
It will help to prioritize your needs and wants. Once you've examined what you can afford, you might even be able to include some important "wants" into your budget.