Create a budget
One of the biggest challenges in creating a budget is coming up with a format that fits your teen's personal situation and needs. If it's too complicated or time-consuming, he or she may lose interest, and if it doesn't truly capture spending habits and expenses, it's not going to help highlight areas where changes can be made.
Here's a straightforward worksheet you can use as a jumping-off point to at least begin to track monthly income and expenses. For items that occur more or less frequently (e.g., being paid weekly or having quarterly insurance premiums), convert them into monthly amounts.
To come up with estimates in the various categories, try to balance between realistically reflecting actual expenses and setting targeted spending levels that will enable you to save money and pay off debts. Compare progress from month to month so you can look for ways to further reduce expenses and more realistically set budgeted amounts.