The common thing to do is to start your own company, pay yourself minimum wage and take the rest as dividends which get taxed at 20%. Then you also get to expense certain things and reduce your tax liability further.
It also screws over single earners significantly. A household where a single person makes 60k is _significantly_ worse-off than a household where two people make 30k each. Having your own company allows you to hire your SO and thus get double the tax free allowance even if only one of you is working.
It creates a tragedy of the commons situation. Anyone not doing the above gets absolutely shafted by the tax man. Anyone doing that, is taking advantage of everyone else paying full tax. As more and more people do that, less people are paying tax, so the government raises taxes further squeezing the middle class.
Edit: some people in the comments are saying this is not true, so it may not be. I don't do this, so I wouldn't know. Friends say they do this and have been trying to convince me that it's worth it. I don't know the exact details and I'm starting to doubt myself.
Further edit: Had to check, but indeed the tax on dividends is lower. So between £12,571 to £50,270 your income is taxed at 20%, but as dividends it's 8.75%. Then regular income over 50k is taxed at 40% whereas dividends are taxed at 33.75%. You also don't pay national insurance on your dividend earnings, which further lowers tax. I'm guessing the 20% figure I was told is what it averaged out as. Sources: