Holidays and traditions go hand in hand. The Christmas season is huge on tradition and families all over the globe celebrate their the holidays in their own unique ways. Ways that have been handed down from one generation to the other for, in some cases, centuries.
Holidays and traditions can mean anything from the foods that are served, to the ceremonies or rites performed and attended by so many, to the whole family converging on grandma's house, to who gives what gift to whom.
No two traditions are the same and vary from family to family and country to country. Everyone looks forward to be able to be a part of something so sentimental and precious that they do all they can to continue the ways of their ancestors and predecessors.
Recipes get handed down from generation to generation and the young ones get taught how to cook the meal and decorate the house so everyone can enjoy themselves thoroughly throughout the season. The ways the food is prepared and how it tastes is as much a part of the way of doing things as any other part of the celebration so the young ones coming up learn to do things "just like Grandma".
It doesn't have to be just Christmas either there are plenty of people who celebrate Thanksgiving, or Memorial Day, or any other of the special days of the year the same way every year. Any of the special days of the year are subject to some type of traditional feast or celebration.
Some stress may enter the situation when two people get married and then have to combine both sides ways of doing things. Compromises surely have to be made to accommodate both families especially if the marriage is an interfaith marriage, same sex marriage, or interracial marriage. Not everyone celebrates things the same way.
To learn to combine traditional festivities, each of you should sit down with pen and paper and outline everything that is important to each one of you when it comes to whatever celebration is in the offing. Then rate each item on each list from most important to least important or at least something that can be left off the combined list that no one cares that much about.
When the two of you have been married and kids come along you can customize your own celebrations and ways of doing things. Some people go out to see a movie in the theater after the feast. Others sit down and watch the football game on TV. Maybe you like to all go sledding or tobogganing, have a snow ball fight or build a snowman in the front yard. (If you live in a place that gets snow, that is.)
Holidays and traditions are what you make them and if your family has been doing things a certain way for as long as you can remember then you might as well leave well enough alone and just enjoy yourselves as best you can.