Luckily, my hubby and I both come from quite small families, so Christmas has never been particularly stressful for us.
My favourite way to spend Christmas is just to two of us with maybe an evening visit from friends.
We always have to go and see Barry's Mum Christmas morning but only for an hour or so, and she spends Christmas day with his sister, so thankfully we've never had to do more than that.
My parents live a distance and a ferry ride away, so I tend to go visit them for a weekend, a week or two before Christmas and spend some real quality time with them, although I have spent the occasional Christmas with them as I recall.
So I don't have any special tricks - we just make Christmas Day our day to spend as we like, not as hordes of family demand.