Ummmmm I have ZERO experience with filing for taxes. My extent of tax knowledge goes to setting up my LLC for a game studio (which tax wise is handled by a hired accountant) and filling out my payroll information for work lol...
Buuuuuttttt the way I handle my expenses when it comes to being a game designer... Say I go to a convention and I spend money on a hotel, food, inventory, handouts, employees, etc... during that time period. I will keep a record (receipts if possible) of all that and when the time comes, which is October where I filled my LLC, I will make sure that my accountant has all my expenses prepared to put into the tax forms.
So my advise is this... keep track of all film expenses very precisely, then when you file your individual taxes at the end of the tax year, simply hand all that information over to the people you pay to do your taxes (H&R Block or whoever you use), they will know if you can deduct it as expenses and whatnot. Or of course you could hire a personal accountant.