1. Take every business deduction

Every legitimate Schedule C deduction reduces both income tax AND self-employment tax — a double benefit. Track expenses contemporaneously. The categories most often missed: home office, vehicle mileage, internet, phone, software subscriptions, professional development, and bank/processor fees.

2. Fund a retirement plan

SEP-IRA (20% of net SE earnings up to the cap), solo 401(k) (combined employee + employer contributions, larger at lower income), or SIMPLE IRA. Reduces income tax dollar-for-dollar. The single biggest lever for self-employed taxpayers.

3. Claim the QBI deduction

20% of qualified business income deductible below the line. Free money for any business below the threshold. Above the threshold, plan around the W-2 wage and SSTB rules.

4. Self-employed health insurance

100% of premiums (medical, dental, vision, qualified LTC) deductible above the line, reducing AGI. Doesn't reduce SE tax but reduces income tax dollar-for-dollar.

5. Home office and accountable plan

Sole prop: claim home-office deduction directly on Schedule C / Form 8829. S-corp: use an accountable plan to reimburse owner home-office expenses tax-free. Either way, capture the deduction — most taxpayers leave it on the table.

6. Section 179 / bonus depreciation

Front-load equipment depreciation in profitable years. Section 179 to fine-tune to a target income; bonus to deduct without income limit.

7. HSA

Triple tax benefit (deductible contribution, tax-free growth, tax-free qualified withdrawal). Available with HDHP coverage. Fund max each year and treat as a stealth retirement account if cash flow allows.

8. S-corp election (when income justifies)

Once net profit comfortably exceeds a reasonable salary, the S-corp can save thousands in payroll tax annually. Cost is bookkeeping, payroll, and state filings. Break-even is generally somewhere in the $50K-$100K profit range.

9. Roth conversion in low years

Convert pretax IRA balances to Roth in low-income years (start-up, sabbatical, post-NOL). Locks in lower rates and creates tax-free future income.

10. Quarterly tax discipline

Pay estimated taxes on time. Project income and tax quarterly. Adjust withholding (if you have W-2 income too). Year-end surprises are usually planning failures.

Common mistakes worth avoiding

The recurring mistakes filers make on this topic cluster in three patterns: (1) optimizing for current-year tax at the expense of multi-year tax, (2) treating the choice as binary when the IRS framework actually allows nuance (partial elections, hybrid methods, year-by-year reassessments), and (3) deferring the analysis until the return is due rather than running it during the year when the result can still influence behavior. A short annual review — even thirty minutes — catches all three failure modes and replaces vague intuition with documented reasoning.