Contractors & the trades
Job costing, ST-124 capital-improvement paperwork, and the W-2/1099 line that New York actually enforces.
Auto repair & HVAC
Parts versus labor on the sales-tax return, service versus install, and the Certificate of Authority under the right legal name.
Salons & barbers
Services are exempt outside NYC, shelf product is not; booth-rent versus employee treatment for the people in your chairs.
Restaurants & food service
Tips, sales tax on prepared food, and a P&L that separates food cost from everything else.
Retail shops
Inventory, sales tax by county, and clean monthly numbers when the register and the bank don't agree.
Real estate investors & agents
Schedule E, K-1s, basis tracking, and the LLC-per-property question answered before the closing, not after.
Trucking & e-commerce sellers
Multi-state filings, marketplace sales tax, and books that survive a lender's or a platform's review.
Professional practices
Consultants, agencies, and solo practices that need real financials and a tax plan, not a shoebox in April.