The effective tax rate is closer to 30%+ once you factor in corporation tax but the rest is correct. You incorporate a limited company and take a low salary and rest in dividends.

Though you'll get to higher tax brackets with that pretty quickly too, so will likely want to leave a fair share of revenue in the company (you still need to pay 20% corp tax on profit), or put it into your pension (tax relief on up to £40k/y).