I think it's worth filing Schedule C and identifying deductions. There may be a tipping point as a solopreneur in terms of income and when you might want to incorporate instead. I'm not an expert here, though. Can I can connect you with a tax professional I trust who can help you out?
TALK TO AN ACCOUNTANT, or at least a bookkeeper who is a certified tax preparer. Every business situation is unique, there are significant variations in tax parameters between local, state and federal levels, and mistakes can be a HUGE problem.
This is an easy answer. Your only option is actual expenses. There is no such thing as a maximum deduction for a business. There's no standard deduction for a business, and how could there be? Some businesses make $100, others make $1,000,000.
You are required to report your actual expenses on Schedule C.
You may qualify for the new 20% pass through deduction, but that won't be part of Schedule C, and it also does not permit a taxpayer to not accurately report the deductions of their business on Schedule C.
As an accountant, I recommend that you set a time weekly, daily, or monthly (depending on the volume of your business) to work on your record-keeping. You can also use the advice of an accountant or online resources to figure out what categories you should focus on.
If you file as a corporation or multi-member business, keep in mind the same principles apply- no standard write-off exists.
Tax Deductions ?
File honestly and accurately. The last thing a small business needs is to have any taxing authority on their backs. No time for that when trying to make a living. Use all the legitimate deduction you qualify for and no more to stay out of trouble. They can come back on you for years.
Been there, done that, and got the T-Shirt.