Assemble your financial information. Whether you are filing your taxes for real or for practice, you will need information on all of the income you received during the year, including salary, wages, dividends, interest, retirement distributions and other income. Wages and salary are officially reported on Form W-2, while interest and investment income are reported on Form 1099. Other forms such as Form K-1, which report distributions from partnerships, are not as common but may pertain to you as well.
List your deductions. The federal government grants you a standard deduction that varies from year-to-year and is based on your family status. For 2012, if you are a single filer, your standard deduction is $5,950, according to the IRS. If you have additional tax deductions in excess of this amount for charitable contributions, state taxes paid, business expenses or other allowable deductions, you can deduct the actual amount of your total deductions rather than using the standard deduction of $5,950.
Download IRS instructions. Every IRS tax form comes with instructions that will help you practice filling them out. The IRS website provides printable instructions that will help you understand which forms you might need to file depending on your individual tax situation.
Obtain sample tax forms. You can download all tax forms from the IRS website, including the commonly used Form 1040. You can fill out most forms online and print them out, or you can simply print out blank copies and fill them in by hand.
Follow instructions and complete your taxes. Enter all of your income and deductions on your tax form following IRS instructions. Transfer values as directed from individual schedules and worksheets to the appropriate portion of your Form 1040. Double-check that all of your math is correct.
Use an online tax service. Sites such as Turbo Tax have free versions of online tax software that you can use to practice completing your taxes.