I haven't really cut back, as we (my family and I) have been doing the same for years. I never buy new decorations etc.; I already have plenty, and buy a few from charity shops. I also make things (e.g. I have made a little snow covered village out of old children's bricks and cardboard). We'll have a real tree this year which I will buy after 21st, so cheaper, and I look for the wonky ones!
For the adults, we give each other books, second hand from charity shops, and I sometimes make edible gifts like Moroccan spiced lemons, biscuits etc. I end up getting quite a few things for my two granddaughters, but again bought from charity shops. I've been re-using wrapping paper/gift bags for over 10 years, so no expense there.
I cook everything for Christmas Day, and I love doing it. I used to cook for my living, but getting a bit too tired (ME/CFS) and old (68) to do much anymore, but I LOVE doing it for all my family here on the day, especially my daughters and granddaughters who live quite a long way away.
So basically cheap and cheerful, but just as full of love and warmth as one costing £££s!