Nit - as far as I know in US this standard deduction applies only to overall household income. It does not apply to Schedule C (aka small business tax return form). For Schedule C you really have to itemize what you spend your money on and keep receipts for some time in case of an audit.
This comment conflates several things and risks confusing others.
Schedule C (self-employment), which is a schedule you attach to your personal income tax return vs a business tax return (different depending on the type of business and what they're reporting) filed by the business.
Itemizing deductions (Schedule A) vs reporting/deducting expenses as part of a Schedule C as required by the IRS.
