Cut out unnecessary stuff like Christmas eve boxes, December 1st boxes, matching pyjamas, duvet sets, cards.
Instead of expensive days out, have walks at country parks, many have trails on. A nice hot drink from a thermos. Or look at the lights after dark. Invite friends round to play, or for an evening drink.
Stay out of shopping centres and supermarkets where possible to avoid the consumerism.
Charity shops have nearly new gifts, often you can't tell. Books, games, toys. Facebook marketplace is great for children's wooden toys or big play kitchens etc. No building big toys is a bonus too.
Keep it simple, you don't need to buy loads of expensive booze and snacks and sides and treats. Just do a normal shop including a roast and a few packs of pigs in blankets plus chocolate coins.
Don't bow to the pressure. Most Christmas spending is pointless.