We live abroad and travel "home" for Christmas. We live with our parents, a few days with the one and a few with the other. We meet my brother and his family and DH's brother and family when we are there. It costs us 2 plane tickets + either train tickets or a rental car. If we are lucky, the parents will pick us up and we don't need a rental car. Both parents to not live near a train station. :-(
An alternative is driving all the 1000 kms from home, including spending the night on board a ferry and renting a cabin onboard. Then we will have a car and good flexibility there. Often flying is cheaper and it is definitively faster. This year we are flying the Mustachian way and bought tickets on the cheapest days.
We buy some presents for each other, but not very expensive stuff. No-one gets an iPhone, but we typically give a self-made photo calendar, slippers, children's tøys.
My mother has for years only give us money (boring). Eventually even my brother started giving me money, because he was not inspired on what to give. I once suggested that we adults could just stop buying each other presents and just get something for my brother's children. This is what we have been doing for some years. Still, they get our homemade photo calendar, and my mum still gives us each a chocolate letter.
At FIL's family, we still give every person a present. Usually he gives me a paper book, while I prefer to read Kindle books. But those cannot be put under the Christmas tree. This year he asked, so I could ask for a new household item that needs replacement. BIL and us have exchanged wish lists, so we buy something that the other appreciates. Last year we received a satiric, daily cartoon calendar from them, that we still enjoy every day. They also have children now, so we buy some stuff for them. DH is this year also sewing some gifts, a dinosaur shirt and pants for his little nephew and an outdoor coat for his father, who needed a new such coat.
For the dinner, FIL has told us he wants to cook a simple dinner for us (5 adults + 2 children) 1 night. We need to provide a 2 course Christmas dinner and BIL needs to do the same thing the next day. FIL will provide desert for both days, probably homemade ice cream. We have done this before and then bought some really nice meat, not very Mustachian, but a once a year quality. We try to keep the other ingredients affordable.