There's a principle concept that every expense has to be for the purpose of doing business. If it's not, then it will get hit with income tax, and sometimes even payroll taxes.

In practice nobody really monitors these things and many do abuse the system to cater for themselves etc. However if you find yourself an enemy who will report you (even just on suspicion), then you better have a convincing case for the tax authority and/or judge as your accounting gets audited.

There are a bunch of special benefit rules that can be used for lawful cost savings though. There are lawful ways to split car costs with company money, there are lawful ways to get a tax-free daily allowance if you're traveling for business, limited to some X days per month.

In general I think the company tax rates are low enough to do everything lawfully. Taking out profits as an owner incurs a 20% income tax to the company and zero taxes to the individual. In addition, if you've taken out profits before, then the company income tax is 14%, up to the amount that equals the average of the last 3 years. So if you take out similar profits on a regular basis, the tax rate is only 14% on everything.