We are comfortably middle class, not upper class (true upper classes actually bleed a lot of money on heating bills and house maintenance and staff).
We don’t use childcare. Ours are old enough now to be out of nursery, but we both do work that isn’t FT so one or usually both of us is around for school runs and school holidays. We only use holiday clubs if kids want to go, not for the childcare cover.
We make a lot of money. This helps! We have a sizeable mortgage (£500k on an £800k house). We are aiming to pay it off within 10 years of buying our house though. We overpay the max of £50k each year. There is no secret to that other than just making more money than we need to spend on keeping ourselves alive, which means that we can drop as much into the mortgage as possible.
We drive secondhand cars. Mine is a 2011. Cost me £6k. I love it. It runs great. No need for £500 a month on car finance.
We are fairly self sufficient. We grow some of our own food, including animals for meat. Because we have the land to do it. We also save a lot on heating because we run wood burners with free wood. A tree falls down and we process it and have space to season it and store it. We do a lot of our own DIY, house/car repairs because we have the time and resources, so those costs are low.
We also have a business set up as a limited company, as many well off people do. It’s a legit business. We have employees, all properly set up with PAYE and workplace pensions and the lot. But it’s hugely cost effective to run purchases through a company that can also be used for other things. We had to make improvements to a barn for work. The business pays for it, but ultimately it’s adding value to our property. I needed a new laptop, bought it through the business, because it’s legitimately for work, but now we have an extra family laptop for the kids to do homework on. That’s £700 we don’t have to spend from our household budget. These things seem minor, but they all add up and mean more capital and more disposable income that someone employed doesn’t have.