Well I don't know about extreme but in general I would say the best way to save is either to increase your income or reduce your outgoings - obviously both are highly dependent on individual circumstances but increasing your income tends to be most effective, so if you are able to get a promotion or pay rise at work, work overtime or extra shifts or even get a second job or 'side hussle' (urgh hate that phrase but the concept is fine, there are useful threads on the money matters board for things like 'earn £10 a day' doing things like online surveys and market research), if you have a regular 9-5 job doing bar work in the evening or a retail/supermarket shelf stacking type jobs at the weekends is tiring but can be a useful 2nd income stream, even if it's minimum wage if you direct all your earnings straight into savings that can be several hundred pounds a month towards your house deposit.
Also, make sure your money is working for you, so if you are a FTB make sure to use the government ISA schemes for your savings, have you got a credit card that gives cashback (obviously make sure to pay in full), some current accounts give rewards and interest too. Obviously check you are on the cheapest possible rates for utilities, internet, insurances etc and never auto-renew, always shop around for the best deal. If you have a contract phone don't upgrade at the end of the contract, keep the older phone and switch to a sim only deal which can save £30-£40 a month, obviously not much but its still a few hundred a year, every little helps.
On the reduction of outgoings front, while a lot of common 'tips' you read online and in media focus on reducing frivolous spending on things like takeaways and 'treats', I found the most effective thing if you are prepared to make major sacrifices is to look at wherever you spend the most money. For most people that's housing and transport, now obviously if you have 3 children with special needs moving into a cheap room in a house share isn't possible or if you are disabled you might not be able to sell your car and walk to work or get the bus, but the people I know who've been able to save a house deposit without major assistance from family or being very high earners have done it through living very very cheaply for a number of years. E.g. living with parents rent-free or in a very cheap bedsit or house share, no car, cycle/walk or public transport everywhere (car club or car hire can be a good option for the odd occasion where you really need a car), no holidays etc. If you are saving £500 a month say by taking these measures, but to lighten up the grimness you spend £100 a month on a takeaway and getting your nails done, that's still £400 net saved. Compared to just cutting out the takeaway and nails but keeping an expensive car on lease, renting a nice flat and having an annual foreign holiday, where you'd only then save £100 net (sorry I don't know if this applies to you as you don't give any further details, but you get the idea).