Claiming the Deduction
To deduct your hobby expenses, you must claim them on line 23 of Schedule A, in the section for miscellaneous deductions. Schedule A is the form used to claim mortgage interest, charitable donations and other itemized deductions. If you don't normally itemize your deductions, and instead take the standard deduction, you may not get any benefit by claiming your hobby expenses. If you do claim the expenses, you must reduce the amount of hobby expenses and other miscellaneous deductions by 2 percent of your adjusted gross income.
You can only claim hobby expenses up to the amount of your hobby income -- you can't claim a loss. The IRS figures you would have spent the money on your hobby anyways, and you weren't doing it to make money. If you ever turn you hobby into a business, you will be able to fully deduct all your expenses.