For me, it's two things. Firstly, the celebration of Jesus's birth and life. That doesn't mean it's his birthday, it should be noted - I know it's not, everyone knows it's not. I don't care, that doesn't mean I can't be reminded on a year-by-year basis to take the time to set aside a few minutes and celebrate the birth/life on a different day.

The other thing is the more obvious one, which is to spend time with the ones you love and make them happy by doing more than you usually would for them. This can be in the form of gifts, services (which can be given as gifts, if you wish), time, efforts, whatever.

People who say it's all about money haven't had an adorably cute hand-made gift given to them by a child at any point in their life. I can get a nice new toy but I'll treasure some of the cards I got from my younger siblings for life.