Unfortunately, there is no official list of performer deductions on the IRS website. All you will find is an explanation that the expense must be "ordinary" and "necessary" for your business in order to pass muster with an auditor. But that is certainly far too vague a concept for the imaginative minds of most actors.
There are several areas that always cause substantial frustration for entertainers. These include the money they spend on hair, makeup, nails, clothing, and gym membership. In general, these are areas you should avoid when it comes to deductions, unless you can define very specifically how the expense applied to your business.
You can write off makeup used for stage or photo shoots, but not if you wear the same makeup during your normal day. And any makeup purchases you intend to deduct should be made from professional suppliers, not your local drugstore. The same applies to your hair-care costs. Don't try to pretend that because you are a performer, you must always look your best to move ahead in your career. Any business professional can say the same thing.
Clothing is always on the IRS watch list. It doesn't matter if you wear something only for auditions. If it can be worn on the street without being considered a costume, it's not deductible. If you purchased the costume for a play or showcase, then keep some production photos to prove it.
Gym membership is never deductible. I have even seen the IRS try to deny dance classes because it considers them to be exercise rather than education.
For several expenditure areas, you will need to be able to document on paper your business use of the item. Just because you have a cell phone or regularly use the Internet for business doesn't mean you're automatically allowed to deduct any part of its cost. If the business percentage of your use is considered too high, many examiners will deny the deduction out of hand. You must be able to prove it.
I realize it's a huge bother, but if you want to write off your film and theater tickets or your DVD rental fees, you must keep some sort of viewing log. It can be as simple as jotting down a few notes in the program when you go to the theater. No one is expecting you to write a complete review of the show, but you need to describe its educational value to you as a performer. Notes on who directed it and cast it or something about the actors should suffice. For example, you may not learn anything when you attend an Adam Sandler film, but it is your job to know his style.
Organize your expenses by category, add them up, then store everything in envelopes or plastic bags so they remain together. You should compare your totals to what you spent last year, to make sure you aren't claiming too much or too little in any area. Most good preparers will want to see a category breakdown, as it helps convince them that your imagination hasn't been too active.
Whatever you do, don't make up your numbers. Tell the truth. You may think you're saving a few dollars, but it will cost you so much more in time, frustration, and penalties if the IRS catches you in a lie. Remember, if the IRS finds significant errors on one year's tax return, it has the right to investigate two additional years immediately.