Estimate your non-income-based tax expenditures for the last 6 months. Consider sales taxes, excise taxes, and personal property taxes. To estimate your personal properhJ taxes, consult your tax statements or talk with your parents about the taxes on your vehicle (if applicable). To estimate your sales taxes, call the applicable state Department of Commerce to determine the tax rates and on what items the taxes are collected. To estimate your excise taxes, call the state Department of Commerce to establish the tax rates on items such as tobacco, gasoline, and alcohol. Excise taxes are also collected on phone usage; to get this figure, consult your phone bill.