Keep your eyes open for regular events, eg tradition here for the kids to have a Terry's choc orange each, and Tesco have them on offer around Sept / Oct at 75p each.. a little saving but it all adds up! Ditto B&M's 2 toys for XX in around Sept for young children.
Sales are on in shops throughout the year so it pays to have a look online & get anything that's good value.
I've already ordered Christmas wrap in the sales online for next year, but Asda's normal price for a large roll was only £1 each when I ran out, good value.
This year I cba sending cards to anyone outside the family unless they sent one to me first - why have I never done this before? I HATE the sitting-down-writing-damn-cards-for-hours job.. only had four or five to send, close family I get special ones for (Card Factory but they aren't as cheap as they used to be) and friends cards go in with their pressies to post (if they live far away) and I post in Nov, NOT Dec! I now have plenty of cards left for Xmas '22..
As regards food, I dislike cooking anyway, so I get the turkey joints in foil tins from Tesco. LOTS of them. It's a game changer.. :-) Kids like the Aunt Bessie stuffing balls. The veg is all fresh but the week before Christmas, supermarkets sell at about 29, 19p a bag for spuds, sprouts etc.. :-)
Oh, & why would anyone want a Christmas Eve supermarket delivery? Too late then, especially for a non driver like me, to get to a shop & buy anything that was out of stock. I aim for the 22nd Dec.
Whatever you can do to make life easier is my mantra! :-)