What types of things are tax-deductible (Washington State)?

Context: I work as a freelancer in the film/commercial industry. When I get a job, it's always either via invoice or short-term payroll. I currently work in the logistical production side of the industry but I also frequently buy things that help further my endgame goal of becoming a creative writer/director. I... show more Context: I work as a freelancer in the film/commercial industry. When I get a job, it's always either via invoice or short-term payroll. I currently work in the logistical production side of the industry but I also frequently buy things that help further my endgame goal of becoming a creative writer/director. I have a personal office in my apartment. I buy supplies for my home and mobile office, buy coffees/ small meals while I write in public places, I go to movies to understand how the industry is trending and to get inspiration for my creative work.

How much of this is deductible in terms of it being a cost of work/development for my business, creative and logistical?

Bullet Examples:

-Coffee/food at public interviews
-Coffee/food while working publicly
-Office supplies for working from home & while working on-location.
-Seeing and buying movies/books for research (education?)
-Traveling mileage to work-related destinations (i.e. to shooting location from my home & working in public from home)
-Depreciating my car if over 75 percent of use is related to work/the above. Is this void if claiming mileage?

Detailed answers directly pertaining to the above are particularly appreciated.
Update: Additional Bullet:

-Anything that would be considered "the cost of networking" such as going to paid events like screenings/festivals that are primarily attended for the networking opportunity. I'm also curious about going out to dinner/drinks with colleagues specially for the purpose of networking.
Update 2: For this industry, these sort of things are considered an expense to growing your business (yourself as the product) just as you would take clients out to dinner so is it feasible that I could argue for these to be at least partially deducted?
Update 3: Please leave this question in Business and Finance > Taxes > United States
4 answers 4