Dislaimer: I'm in Belgium but from the answers already posted I think some ideas might still be relevant to UK.
First things first, TomTom is very right to advise you to discuss that with your accountant. They can probably better than anybody here advise you on things to do, things to avoid doing, etc... How you choose your accountant will also probably depend on the approach you want to have, from playing strictly by the rules to basically trying to buy everything you buy through company money. I think you shouldn't overlook the importance of having a good relationship with your accountant, having them respect your approach and guiding you with it.
Now, to extend a bit on "how can I turn more company money into personal advantages?", because that's a question I've been asking me in the past 2 years, here are a few examples which may or may not be relevant for you (depending your kind of business, I'm in IT) or for UK, but are I think worth exploring. Please note I'm only mentioning things I have been doing or have seen other freelance friends do without any issue. I can not guarantee how legal this may be at a given time in a given place, but they seem to me to be in some kind of grey zone.
Every IT/Multimedia hardware or office material you can think of : Nice desk, nice office chair, top notch computer, printer, smartphone, headphones, network material... Then maybe your meeting room needs a big screen? Or a big table and some chairs? If this meeting room is your living room, this can be convenient...
Now there's no meeting without coffee, so you need a coffee machine. And the coffee machine needs coffee, so your company also have to buy coffee.
You can finally legally use this expensive software, reward the developers of that freeware you've been using for years, go "premium" on these cloud services you're using,...
Your company could be investing in real estate, buying a house on the seaside for example (or in a foreign country), for it to be rented during the year, and your country house whenever you feel like it. (note: in Belgium doing so is considered a "personal advantage" which is taxed later on).
Additionally, your company may simply be paying you (as an individual) a rent for the office space located in your house.
Some go up to the extent where your company is actually buying your house, but I'm not a big fan of that approach...
This may well be a very Belgian thing because company cars are a huge thing here, but my (self-owned) company owns my car and pays for any expense related to it (including insurance and fuel). Here also it is considered a "personal advantage" so I'm personally taxed on it as it was part of the salary, but it's nowhere near the cost of the car.
My company pays a top notch health insurance for my whole close family.
Besides this, I also have some insurance so that if let's say I fall and break both my arms so I can not work, I have a guaranteed income up to several years in the future. Linked to that I have a life insurance/pension plan so that if I die tomorrow the future of my family should be OK financially speaking, and if I happen to live until retirement I'll get additional money on top of "normal" (state issued) retirement money.
At some point, we may be authorized to travel again... you can probably be creative a bit on that. Attending a conference in San Francisco or simply Amsterdam or Paris can have some side advantages while still being professionally justified. If your company can afford it you can also maybe upgrade your travel experience, going business class instead of eco.
Maybe you're already, as an individual, helping one or another charity, you can probably help even more with company money. Donations are commonly tax-exempt.
I mention it because you do so in your question, but not being much into fashion myself, and usually working in very casual environments, this is such a small budget I don't even want to try putting this on my company. Still it may be possible depending on your kind of business to buy nice suits or shoes or a part of your more casual workwear through your company.
It's common practice for companies to offer gifts to associates, clients or prospects. This can include chocolates, champagne, food baskets, retailer gift cards,... whether all of this is actually (fully or partially) given to clients and prospects, and how much of the "leftovers" you actually use for your own benefits is hard to control.
Once again maybe a very Belgian thing, but it happens that here the income you get from selling such rights is much less taxed than your salary income. Hence you can "sell" the rights on my intellectual property (a percentage of my company's yearly income) to your company, get that money on your private account, but pay much less taxes on it than if you got the same amount as a salary.
Whatever you do I think the key is to be reasonable, trying to stay below the radar, following the advise of your accountant. At least it's an approach that seems to be working for me.