Lets take a moment to look at the low hanging fruit of creativity which we haven't applied so far.
Holidays become offsites (One of my contractors is still trying to crack Australia despite annual trips going back a decade). That he happens to hail from there is pure coincidence, as is the fact that his family farm is there.
Holidays become training courses - One of my guys takes 3 weeks off every year and goes abroad with the family - he just does one cert a week at each end of the holiday. All employees you see.
The first 2 years at an employer mean on top of the mileage claims you can expense your train ticket - one of my mates does this and he comes down to London from the east mids every day. Hell, my ticket costs 350 notes a month and I get nothing for that because HMRC think I might want to go back into London on a night for leisure!!
We've not looked at structuring yet, where your onshore company buys services or equipment through an offshore provider, located conveniently in a tax friendly jurisdiction.
Club access - golf, social etc are easily obtainable through your company before taxes become due.
We're not even getting close to a grey area here - its all legal and firmly so.
If we want to go grey we start looking at director loans, corporate financing across a web of companies owned by relatives, etc
I've a former colleague with a lovely range of boss suits with his corporate logo embroidered very discreetly on the cuffs, which is a corporate uniform, along with the hermes and churches.
Charity donations, when either you benefit from attending the functions, or where you might even run the charitable trust yourself.
Then we can look at where you keep you corporate IP (Holland is apparently efficient for tax reasons and might work for You Too).
We haven't looked at business development grants, we haven't looked at R&D deductions, or corporate investments or a whole host of things.
Up to this point I personally know someone engaging in each of the above, so making out like contractors don't do this is simply not going to wash.
Then we can go dark, balls out evasion from there or even straight up fraud, which is not something I'd engage in professionally or personally, but lets not pretend it isn't happening and that the losses to the tax man aren't real. I'll not detail how this is most easily done for reasons which should be obvious.