welcome leboob. Meal planning and creative use of what you already have saves money. Also thinking outside the box, like making cheap things like pitta breads.
Swapping to Aldi or lidl if you have one. Mysupermarket is a good app as it tells you the cheapest place to buy things.
Staples like rice you can buy in big bags much cheaper, I always scoffed at Tilda rice but ipsos proved me wrong, it's much better rice. Farm shops or morrisons do big bags of spuds cheaply if that's your staple starch. Huge bags of pasta in asda are really good value.
Shops like b&m do big bags of teabags cheap, or sainsburys smartprice tea is really nice.
Shopping apps like shopitize, checkoutsmart & quidco clicksnap or topcashback give cashback on certain items or free things. Topcashback pays in Tesco points so you can boost to 3-4 times the original value. Eg I claimed £2.99 recently that is £9 in hotel vouchers.
East end spices are much cheaper online than the supermarkets.
I'm going to do a musclefood order in the week rather than buy meat in the supermarkets.